diff dep/fmt/test/format-test.cc @ 343:1faa72660932

*: transfer back to cmake from autotools autotools just made lots of things more complicated than they should have and many things broke (i.e. translations)
author Paper <paper@paper.us.eu.org>
date Thu, 20 Jun 2024 05:56:06 -0400
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dep/fmt/test/format-test.cc	Thu Jun 20 05:56:06 2024 -0400
@@ -0,0 +1,2295 @@
+// Formatting library for C++ - formatting library tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+// Check if fmt/format.h compiles with windows.h included before it.
+#ifdef _WIN32
+#  include <windows.h>
+#endif
+// clang-format off
+#include "fmt/format.h"
+// clang-format on
+
+#include <stdint.h>  // uint32_t
+
+#include <climits>      // INT_MAX
+#include <cmath>        // std::signbit
+#include <cstring>      // std::strlen
+#include <iterator>     // std::back_inserter
+#include <list>         // std::list
+#include <memory>       // std::unique_ptr
+#include <type_traits>  // std::is_default_constructible
+
+#include "gtest-extra.h"
+#include "mock-allocator.h"
+#include "util.h"
+
+using fmt::basic_memory_buffer;
+using fmt::format_error;
+using fmt::memory_buffer;
+using fmt::runtime;
+using fmt::string_view;
+using fmt::detail::max_value;
+using fmt::detail::uint128_fallback;
+
+using testing::Return;
+using testing::StrictMock;
+
+enum { buffer_size = 256 };
+
+TEST(uint128_test, ctor) {
+  auto n = uint128_fallback();
+  EXPECT_EQ(n, 0);
+  n = uint128_fallback(42);
+  EXPECT_EQ(n, 42);
+  EXPECT_EQ(static_cast<uint64_t>(n), 42);
+}
+
+TEST(uint128_test, shift) {
+  auto n = uint128_fallback(42);
+  n = n << 64;
+  EXPECT_EQ(static_cast<uint64_t>(n), 0);
+  n = n >> 64;
+  EXPECT_EQ(static_cast<uint64_t>(n), 42);
+  n = n << 62;
+  EXPECT_EQ(static_cast<uint64_t>(n >> 64), 0xa);
+  EXPECT_EQ(static_cast<uint64_t>(n), 0x8000000000000000);
+  n = n >> 62;
+  EXPECT_EQ(static_cast<uint64_t>(n), 42);
+  EXPECT_EQ(uint128_fallback(1) << 112, uint128_fallback(0x1000000000000, 0));
+  EXPECT_EQ(uint128_fallback(0x1000000000000, 0) >> 112, uint128_fallback(1));
+}
+
+TEST(uint128_test, minus) {
+  auto n = uint128_fallback(42);
+  EXPECT_EQ(n - 2, 40);
+}
+
+TEST(uint128_test, plus_assign) {
+  auto n = uint128_fallback(32);
+  n += uint128_fallback(10);
+  EXPECT_EQ(n, 42);
+  n = uint128_fallback(max_value<uint64_t>());
+  n += uint128_fallback(1);
+  EXPECT_EQ(n, uint128_fallback(1) << 64);
+}
+
+TEST(uint128_test, multiply) {
+  auto n = uint128_fallback(2251799813685247);
+  n = n * 3611864890;
+  EXPECT_EQ(static_cast<uint64_t>(n >> 64), 440901);
+}
+
+template <typename Float> void check_isfinite() {
+  using fmt::detail::isfinite;
+  EXPECT_TRUE(isfinite(Float(0.0)));
+  EXPECT_TRUE(isfinite(Float(42.0)));
+  EXPECT_TRUE(isfinite(Float(-42.0)));
+  EXPECT_TRUE(isfinite(Float(fmt::detail::max_value<double>())));
+  // Use double because std::numeric_limits is broken for __float128.
+  using limits = std::numeric_limits<double>;
+  FMT_CONSTEXPR20 auto result = isfinite(Float(limits::infinity()));
+  EXPECT_FALSE(result);
+  EXPECT_FALSE(isfinite(Float(limits::infinity())));
+  EXPECT_FALSE(isfinite(Float(-limits::infinity())));
+  EXPECT_FALSE(isfinite(Float(limits::quiet_NaN())));
+  EXPECT_FALSE(isfinite(Float(-limits::quiet_NaN())));
+}
+
+TEST(float_test, isfinite) {
+  check_isfinite<double>();
+#if FMT_USE_FLOAT128
+  check_isfinite<fmt::detail::float128>();
+#endif
+}
+
+template <typename Float> void check_isnan() {
+  using fmt::detail::isnan;
+  EXPECT_FALSE(isnan(Float(0.0)));
+  EXPECT_FALSE(isnan(Float(42.0)));
+  EXPECT_FALSE(isnan(Float(-42.0)));
+  EXPECT_FALSE(isnan(Float(fmt::detail::max_value<double>())));
+  // Use double because std::numeric_limits is broken for __float128.
+  using limits = std::numeric_limits<double>;
+  EXPECT_FALSE(isnan(Float(limits::infinity())));
+  EXPECT_FALSE(isnan(Float(-limits::infinity())));
+  EXPECT_TRUE(isnan(Float(limits::quiet_NaN())));
+  EXPECT_TRUE(isnan(Float(-limits::quiet_NaN())));
+}
+
+TEST(float_test, isnan) {
+  check_isnan<double>();
+#if FMT_USE_FLOAT128
+  check_isnan<fmt::detail::float128>();
+#endif
+}
+
+struct uint32_pair {
+  uint32_t u[2];
+};
+
+TEST(util_test, bit_cast) {
+  auto s = fmt::detail::bit_cast<uint32_pair>(uint64_t{42});
+  EXPECT_EQ(fmt::detail::bit_cast<uint64_t>(s), 42ull);
+  s = fmt::detail::bit_cast<uint32_pair>(~uint64_t{0});
+  EXPECT_EQ(fmt::detail::bit_cast<uint64_t>(s), ~0ull);
+}
+
+// Increment a number in a string.
+void increment(char* s) {
+  for (int i = static_cast<int>(std::strlen(s)) - 1; i >= 0; --i) {
+    if (s[i] != '9') {
+      ++s[i];
+      break;
+    }
+    s[i] = '0';
+  }
+}
+
+TEST(util_test, increment) {
+  char s[10] = "123";
+  increment(s);
+  EXPECT_STREQ("124", s);
+  s[2] = '8';
+  increment(s);
+  EXPECT_STREQ("129", s);
+  increment(s);
+  EXPECT_STREQ("130", s);
+  s[1] = s[2] = '9';
+  increment(s);
+  EXPECT_STREQ("200", s);
+}
+
+TEST(util_test, parse_nonnegative_int) {
+  auto s = fmt::string_view("10000000000");
+  auto begin = s.begin(), end = s.end();
+  EXPECT_EQ(fmt::detail::parse_nonnegative_int(begin, end, -1), -1);
+  s = "2147483649";
+  begin = s.begin();
+  end = s.end();
+  EXPECT_EQ(fmt::detail::parse_nonnegative_int(begin, end, -1), -1);
+}
+
+TEST(format_impl_test, compute_width) {
+  EXPECT_EQ(fmt::detail::compute_width("вожык"), 5);
+}
+
+TEST(util_test, utf8_to_utf16) {
+  auto u = fmt::detail::utf8_to_utf16("лошадка");
+  EXPECT_EQ(L"\x043B\x043E\x0448\x0430\x0434\x043A\x0430", u.str());
+  EXPECT_EQ(7, u.size());
+  // U+10437 { DESERET SMALL LETTER YEE }
+  EXPECT_EQ(L"\xD801\xDC37", fmt::detail::utf8_to_utf16("𐐷").str());
+  EXPECT_THROW_MSG(fmt::detail::utf8_to_utf16("\xc3\x28"), std::runtime_error,
+                   "invalid utf8");
+  EXPECT_THROW_MSG(fmt::detail::utf8_to_utf16(fmt::string_view("л", 1)),
+                   std::runtime_error, "invalid utf8");
+  EXPECT_EQ(L"123456", fmt::detail::utf8_to_utf16("123456").str());
+}
+
+TEST(util_test, utf8_to_utf16_empty_string) {
+  auto s = std::string();
+  auto u = fmt::detail::utf8_to_utf16(s.c_str());
+  EXPECT_EQ(L"", u.str());
+  EXPECT_EQ(s.size(), u.size());
+}
+
+TEST(util_test, allocator_ref) {
+  using test_allocator_ref = allocator_ref<mock_allocator<int>>;
+  auto check_forwarding = [](mock_allocator<int>& alloc,
+                             test_allocator_ref& ref) {
+    int mem;
+    // Check if value_type is properly defined.
+    allocator_ref<mock_allocator<int>>::value_type* ptr = &mem;
+    // Check forwarding.
+    EXPECT_CALL(alloc, allocate(42)).WillOnce(Return(ptr));
+    ref.allocate(42);
+    EXPECT_CALL(alloc, deallocate(ptr, 42));
+    ref.deallocate(ptr, 42);
+  };
+
+  StrictMock<mock_allocator<int>> alloc;
+  auto ref = test_allocator_ref(&alloc);
+  // Check if allocator_ref forwards to the underlying allocator.
+  check_forwarding(alloc, ref);
+  test_allocator_ref ref2(ref);
+  check_forwarding(alloc, ref2);
+  test_allocator_ref ref3;
+  EXPECT_EQ(nullptr, ref3.get());
+  ref3 = ref;
+  check_forwarding(alloc, ref3);
+}
+
+TEST(util_test, format_system_error) {
+  fmt::memory_buffer message;
+  fmt::format_system_error(message, EDOM, "test");
+  auto ec = std::error_code(EDOM, std::generic_category());
+  EXPECT_EQ(to_string(message), std::system_error(ec, "test").what());
+  message = fmt::memory_buffer();
+
+  // Check if std::allocator throws on allocating max size_t / 2 chars.
+  size_t max_size = max_value<size_t>() / 2;
+  bool throws_on_alloc = false;
+  try {
+    auto alloc = std::allocator<char>();
+    alloc.deallocate(alloc.allocate(max_size), max_size);
+  } catch (const std::bad_alloc&) {
+    throws_on_alloc = true;
+  }
+  if (!throws_on_alloc) {
+    fmt::print("warning: std::allocator allocates {} chars\n", max_size);
+    return;
+  }
+}
+
+TEST(util_test, system_error) {
+  auto test_error = fmt::system_error(EDOM, "test");
+  auto ec = std::error_code(EDOM, std::generic_category());
+  EXPECT_STREQ(test_error.what(), std::system_error(ec, "test").what());
+  EXPECT_EQ(test_error.code(), ec);
+
+  auto error = std::system_error(std::error_code());
+  try {
+    throw fmt::system_error(EDOM, "test {}", "error");
+  } catch (const std::system_error& e) {
+    error = e;
+  }
+  fmt::memory_buffer message;
+  fmt::format_system_error(message, EDOM, "test error");
+  EXPECT_EQ(error.what(), to_string(message));
+  EXPECT_EQ(error.code(), std::error_code(EDOM, std::generic_category()));
+}
+
+TEST(util_test, report_system_error) {
+  fmt::memory_buffer out;
+  fmt::format_system_error(out, EDOM, "test error");
+  out.push_back('\n');
+  EXPECT_WRITE(stderr, fmt::report_system_error(EDOM, "test error"),
+               to_string(out));
+}
+
+TEST(memory_buffer_test, ctor) {
+  basic_memory_buffer<char, 123> buffer;
+  EXPECT_EQ(static_cast<size_t>(0), buffer.size());
+  EXPECT_EQ(123u, buffer.capacity());
+}
+
+using std_allocator = allocator_ref<std::allocator<char>>;
+
+TEST(memory_buffer_test, move_ctor_inline_buffer) {
+  auto check_move_buffer =
+      [](const char* str, basic_memory_buffer<char, 5, std_allocator>& buffer) {
+        std::allocator<char>* alloc = buffer.get_allocator().get();
+        basic_memory_buffer<char, 5, std_allocator> buffer2(std::move(buffer));
+        // Move shouldn't destroy the inline content of the first buffer.
+        EXPECT_EQ(str, std::string(&buffer[0], buffer.size()));
+        EXPECT_EQ(str, std::string(&buffer2[0], buffer2.size()));
+        EXPECT_EQ(5u, buffer2.capacity());
+        // Move should transfer allocator.
+        EXPECT_EQ(nullptr, buffer.get_allocator().get());
+        EXPECT_EQ(alloc, buffer2.get_allocator().get());
+      };
+
+  auto alloc = std::allocator<char>();
+  basic_memory_buffer<char, 5, std_allocator> buffer((std_allocator(&alloc)));
+  const char test[] = "test";
+  buffer.append(string_view(test, 4));
+  check_move_buffer("test", buffer);
+  // Adding one more character fills the inline buffer, but doesn't cause
+  // dynamic allocation.
+  buffer.push_back('a');
+  check_move_buffer("testa", buffer);
+}
+
+TEST(memory_buffer_test, move_ctor_dynamic_buffer) {
+  auto alloc = std::allocator<char>();
+  basic_memory_buffer<char, 4, std_allocator> buffer((std_allocator(&alloc)));
+  const char test[] = "test";
+  buffer.append(test, test + 4);
+  const char* inline_buffer_ptr = &buffer[0];
+  // Adding one more character causes the content to move from the inline to
+  // a dynamically allocated buffer.
+  buffer.push_back('a');
+  basic_memory_buffer<char, 4, std_allocator> buffer2(std::move(buffer));
+  // Move should rip the guts of the first buffer.
+  EXPECT_EQ(&buffer[0], inline_buffer_ptr);
+  EXPECT_EQ(buffer.size(), 0);
+  EXPECT_EQ(std::string(&buffer2[0], buffer2.size()), "testa");
+  EXPECT_GT(buffer2.capacity(), 4u);
+}
+
+void check_move_assign_buffer(const char* str,
+                              basic_memory_buffer<char, 5>& buffer) {
+  basic_memory_buffer<char, 5> buffer2;
+  buffer2 = std::move(buffer);
+  // Move shouldn't destroy the inline content of the first buffer.
+  EXPECT_EQ(str, std::string(&buffer[0], buffer.size()));
+  EXPECT_EQ(str, std::string(&buffer2[0], buffer2.size()));
+  EXPECT_EQ(5u, buffer2.capacity());
+}
+
+TEST(memory_buffer_test, move_assignment) {
+  basic_memory_buffer<char, 5> buffer;
+  const char test[] = "test";
+  buffer.append(test, test + 4);
+  check_move_assign_buffer("test", buffer);
+  // Adding one more character fills the inline buffer, but doesn't cause
+  // dynamic allocation.
+  buffer.push_back('a');
+  check_move_assign_buffer("testa", buffer);
+  const char* inline_buffer_ptr = &buffer[0];
+  // Adding one more character causes the content to move from the inline to
+  // a dynamically allocated buffer.
+  buffer.push_back('b');
+  basic_memory_buffer<char, 5> buffer2;
+  buffer2 = std::move(buffer);
+  // Move should rip the guts of the first buffer.
+  EXPECT_EQ(inline_buffer_ptr, &buffer[0]);
+  EXPECT_EQ("testab", std::string(&buffer2[0], buffer2.size()));
+  EXPECT_GT(buffer2.capacity(), 5u);
+}
+
+TEST(memory_buffer_test, grow) {
+  using allocator = allocator_ref<mock_allocator<int>>;
+  mock_allocator<int> alloc;
+  basic_memory_buffer<int, 10, allocator> buffer((allocator(&alloc)));
+  buffer.resize(7);
+  using fmt::detail::to_unsigned;
+  for (int i = 0; i < 7; ++i) buffer[to_unsigned(i)] = i * i;
+  EXPECT_EQ(10u, buffer.capacity());
+  int mem[20];
+  mem[7] = 0xdead;
+  EXPECT_CALL(alloc, allocate(20)).WillOnce(Return(mem));
+  buffer.try_reserve(20);
+  EXPECT_EQ(20u, buffer.capacity());
+  // Check if size elements have been copied
+  for (int i = 0; i < 7; ++i) EXPECT_EQ(i * i, buffer[to_unsigned(i)]);
+  // and no more than that.
+  EXPECT_EQ(0xdead, buffer[7]);
+  EXPECT_CALL(alloc, deallocate(mem, 20));
+}
+
+TEST(memory_buffer_test, allocator) {
+  using test_allocator = allocator_ref<mock_allocator<char>>;
+  basic_memory_buffer<char, 10, test_allocator> buffer;
+  EXPECT_EQ(nullptr, buffer.get_allocator().get());
+  StrictMock<mock_allocator<char>> alloc;
+  char mem;
+  {
+    basic_memory_buffer<char, 10, test_allocator> buffer2(
+        (test_allocator(&alloc)));
+    EXPECT_EQ(&alloc, buffer2.get_allocator().get());
+    size_t size = 2 * fmt::inline_buffer_size;
+    EXPECT_CALL(alloc, allocate(size)).WillOnce(Return(&mem));
+    buffer2.reserve(size);
+    EXPECT_CALL(alloc, deallocate(&mem, size));
+  }
+}
+
+TEST(memory_buffer_test, exception_in_deallocate) {
+  using test_allocator = allocator_ref<mock_allocator<char>>;
+  StrictMock<mock_allocator<char>> alloc;
+  basic_memory_buffer<char, 10, test_allocator> buffer(
+      (test_allocator(&alloc)));
+  size_t size = 2 * fmt::inline_buffer_size;
+  auto mem = std::vector<char>(size);
+  {
+    EXPECT_CALL(alloc, allocate(size)).WillOnce(Return(&mem[0]));
+    buffer.resize(size);
+    std::fill(&buffer[0], &buffer[0] + size, 'x');
+  }
+  auto mem2 = std::vector<char>(2 * size);
+  {
+    EXPECT_CALL(alloc, allocate(2 * size)).WillOnce(Return(&mem2[0]));
+    auto e = std::exception();
+    EXPECT_CALL(alloc, deallocate(&mem[0], size)).WillOnce(testing::Throw(e));
+    EXPECT_THROW(buffer.reserve(2 * size), std::exception);
+    EXPECT_EQ(&mem2[0], &buffer[0]);
+    // Check that the data has been copied.
+    for (size_t i = 0; i < size; ++i) EXPECT_EQ('x', buffer[i]);
+  }
+  EXPECT_CALL(alloc, deallocate(&mem2[0], 2 * size));
+}
+
+template <typename Allocator, size_t MaxSize>
+class max_size_allocator : public Allocator {
+ public:
+  using typename Allocator::value_type;
+  size_t max_size() const noexcept { return MaxSize; }
+  value_type* allocate(size_t n) {
+    if (n > max_size()) {
+      throw std::length_error("size > max_size");
+    }
+    return std::allocator_traits<Allocator>::allocate(
+        *static_cast<Allocator*>(this), n);
+  }
+  void deallocate(value_type* p, size_t n) {
+    std::allocator_traits<Allocator>::deallocate(*static_cast<Allocator*>(this),
+                                                 p, n);
+  }
+};
+
+TEST(memory_buffer_test, max_size_allocator) {
+  // 160 = 128 + 32
+  using test_allocator = max_size_allocator<std::allocator<char>, 160>;
+  basic_memory_buffer<char, 10, test_allocator> buffer;
+  buffer.resize(128);
+  // new_capacity = 128 + 128/2 = 192 > 160
+  buffer.resize(160);  // Shouldn't throw.
+}
+
+TEST(memory_buffer_test, max_size_allocator_overflow) {
+  using test_allocator = max_size_allocator<std::allocator<char>, 160>;
+  basic_memory_buffer<char, 10, test_allocator> buffer;
+  EXPECT_THROW(buffer.resize(161), std::exception);
+}
+
+TEST(format_test, exception_from_lib) {
+  EXPECT_THROW_MSG(fmt::throw_format_error("test"), format_error, "test");
+}
+
+TEST(format_test, escape) {
+  EXPECT_EQ(fmt::format("{{"), "{");
+  EXPECT_EQ(fmt::format("before {{"), "before {");
+  EXPECT_EQ(fmt::format("{{ after"), "{ after");
+  EXPECT_EQ(fmt::format("before {{ after"), "before { after");
+
+  EXPECT_EQ(fmt::format("}}"), "}");
+  EXPECT_EQ(fmt::format("before }}"), "before }");
+  EXPECT_EQ(fmt::format("}} after"), "} after");
+  EXPECT_EQ(fmt::format("before }} after"), "before } after");
+
+  EXPECT_EQ(fmt::format("{{}}"), "{}");
+  EXPECT_EQ(fmt::format("{{{0}}}", 42), "{42}");
+}
+
+TEST(format_test, unmatched_braces) {
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{")), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("}")), format_error,
+                   "unmatched '}' in format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0{}")), format_error,
+                   "invalid format string");
+}
+
+TEST(format_test, no_args) { EXPECT_EQ(fmt::format("test"), "test"); }
+
+TEST(format_test, args_in_different_positions) {
+  EXPECT_EQ(fmt::format("{0}", 42), "42");
+  EXPECT_EQ(fmt::format("before {0}", 42), "before 42");
+  EXPECT_EQ(fmt::format("{0} after", 42), "42 after");
+  EXPECT_EQ(fmt::format("before {0} after", 42), "before 42 after");
+  EXPECT_EQ(fmt::format("{0} = {1}", "answer", 42), "answer = 42");
+  EXPECT_EQ(fmt::format("{1} is the {0}", "answer", 42), "42 is the answer");
+  EXPECT_EQ(fmt::format("{0}{1}{0}", "abra", "cad"), "abracadabra");
+}
+
+TEST(format_test, arg_errors) {
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{")), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{?}")), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0")), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0}")), format_error,
+                   "argument not found");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{00}"), 42), format_error,
+                   "invalid format string");
+
+  auto int_max = std::to_string(INT_MAX);
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{" + int_max)), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{" + int_max + "}")),
+                   format_error, "argument not found");
+
+  auto int_maxer = std::to_string(INT_MAX + 1u);
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{" + int_maxer)), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{" + int_maxer + "}")),
+                   format_error, "argument not found");
+}
+
+template <int N> struct test_format {
+  template <typename... T>
+  static auto format(fmt::string_view fmt, const T&... args) -> std::string {
+    return test_format<N - 1>::format(fmt, N - 1, args...);
+  }
+};
+
+template <> struct test_format<0> {
+  template <typename... T>
+  static auto format(fmt::string_view fmt, const T&... args) -> std::string {
+    return fmt::format(runtime(fmt), args...);
+  }
+};
+
+TEST(format_test, many_args) {
+  EXPECT_EQ("19", test_format<20>::format("{19}"));
+  EXPECT_THROW_MSG(test_format<20>::format("{20}"), format_error,
+                   "argument not found");
+  EXPECT_THROW_MSG(test_format<21>::format("{21}"), format_error,
+                   "argument not found");
+  using fmt::detail::max_packed_args;
+  std::string format_str = fmt::format("{{{}}}", max_packed_args + 1);
+  EXPECT_THROW_MSG(test_format<max_packed_args>::format(format_str),
+                   format_error, "argument not found");
+}
+
+TEST(format_test, named_arg) {
+  EXPECT_EQ("1/a/A", fmt::format("{_1}/{a_}/{A_}", fmt::arg("a_", 'a'),
+                                 fmt::arg("A_", "A"), fmt::arg("_1", 1)));
+  EXPECT_EQ(fmt::format("{0:{width}}", -42, fmt::arg("width", 4)), " -42");
+  EXPECT_EQ("st",
+            fmt::format("{0:.{precision}}", "str", fmt::arg("precision", 2)));
+  EXPECT_EQ(fmt::format("{} {two}", 1, fmt::arg("two", 2)), "1 2");
+  EXPECT_EQ("42",
+            fmt::format("{c}", fmt::arg("a", 0), fmt::arg("b", 0),
+                        fmt::arg("c", 42), fmt::arg("d", 0), fmt::arg("e", 0),
+                        fmt::arg("f", 0), fmt::arg("g", 0), fmt::arg("h", 0),
+                        fmt::arg("i", 0), fmt::arg("j", 0), fmt::arg("k", 0),
+                        fmt::arg("l", 0), fmt::arg("m", 0), fmt::arg("n", 0),
+                        fmt::arg("o", 0), fmt::arg("p", 0)));
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{a}")), format_error,
+                   "argument not found");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{a}"), 42), format_error,
+                   "argument not found");
+}
+
+TEST(format_test, auto_arg_index) {
+  EXPECT_EQ(fmt::format("{}{}{}", 'a', 'b', 'c'), "abc");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0}{}"), 'a', 'b'), format_error,
+                   "cannot switch from manual to automatic argument indexing");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{}{0}"), 'a', 'b'), format_error,
+                   "cannot switch from automatic to manual argument indexing");
+  EXPECT_EQ(fmt::format("{:.{}}", 1.2345, 2), "1.2");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0}:.{}"), 1.2345, 2),
+                   format_error,
+                   "cannot switch from manual to automatic argument indexing");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:.{0}}"), 1.2345, 2),
+                   format_error,
+                   "cannot switch from automatic to manual argument indexing");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{}")), format_error,
+                   "argument not found");
+}
+
+TEST(format_test, empty_specs) { EXPECT_EQ(fmt::format("{0:}", 42), "42"); }
+
+TEST(format_test, left_align) {
+  EXPECT_EQ(fmt::format("{0:<4}", 42), "42  ");
+  EXPECT_EQ(fmt::format("{0:<4o}", 042), "42  ");
+  EXPECT_EQ(fmt::format("{0:<4x}", 0x42), "42  ");
+  EXPECT_EQ(fmt::format("{0:<5}", -42), "-42  ");
+  EXPECT_EQ(fmt::format("{0:<5}", 42u), "42   ");
+  EXPECT_EQ(fmt::format("{0:<5}", -42l), "-42  ");
+  EXPECT_EQ(fmt::format("{0:<5}", 42ul), "42   ");
+  EXPECT_EQ(fmt::format("{0:<5}", -42ll), "-42  ");
+  EXPECT_EQ(fmt::format("{0:<5}", 42ull), "42   ");
+  EXPECT_EQ(fmt::format("{0:<5}", -42.0), "-42  ");
+  EXPECT_EQ(fmt::format("{0:<5}", -42.0l), "-42  ");
+  EXPECT_EQ(fmt::format("{0:<5}", 'c'), "c    ");
+  EXPECT_EQ(fmt::format("{0:<5}", "abc"), "abc  ");
+  EXPECT_EQ(fmt::format("{0:<8}", reinterpret_cast<void*>(0xface)), "0xface  ");
+}
+
+TEST(format_test, right_align) {
+  EXPECT_EQ(fmt::format("{0:>4}", 42), "  42");
+  EXPECT_EQ(fmt::format("{0:>4o}", 042), "  42");
+  EXPECT_EQ(fmt::format("{0:>4x}", 0x42), "  42");
+  EXPECT_EQ(fmt::format("{0:>5}", -42), "  -42");
+  EXPECT_EQ(fmt::format("{0:>5}", 42u), "   42");
+  EXPECT_EQ(fmt::format("{0:>5}", -42l), "  -42");
+  EXPECT_EQ(fmt::format("{0:>5}", 42ul), "   42");
+  EXPECT_EQ(fmt::format("{0:>5}", -42ll), "  -42");
+  EXPECT_EQ(fmt::format("{0:>5}", 42ull), "   42");
+  EXPECT_EQ(fmt::format("{0:>5}", -42.0), "  -42");
+  EXPECT_EQ(fmt::format("{0:>5}", -42.0l), "  -42");
+  EXPECT_EQ(fmt::format("{0:>5}", 'c'), "    c");
+  EXPECT_EQ(fmt::format("{0:>5}", "abc"), "  abc");
+  EXPECT_EQ(fmt::format("{0:>8}", reinterpret_cast<void*>(0xface)), "  0xface");
+}
+
+TEST(format_test, center_align) {
+  EXPECT_EQ(fmt::format("{0:^5}", 42), " 42  ");
+  EXPECT_EQ(fmt::format("{0:^5o}", 042), " 42  ");
+  EXPECT_EQ(fmt::format("{0:^5x}", 0x42), " 42  ");
+  EXPECT_EQ(fmt::format("{0:^5}", -42), " -42 ");
+  EXPECT_EQ(fmt::format("{0:^5}", 42u), " 42  ");
+  EXPECT_EQ(fmt::format("{0:^5}", -42l), " -42 ");
+  EXPECT_EQ(fmt::format("{0:^5}", 42ul), " 42  ");
+  EXPECT_EQ(fmt::format("{0:^5}", -42ll), " -42 ");
+  EXPECT_EQ(fmt::format("{0:^5}", 42ull), " 42  ");
+  EXPECT_EQ(fmt::format("{0:^5}", -42.0), " -42 ");
+  EXPECT_EQ(fmt::format("{0:^5}", -42.0l), " -42 ");
+  EXPECT_EQ(fmt::format("{0:^5}", 'c'), "  c  ");
+  EXPECT_EQ(fmt::format("{0:^6}", "abc"), " abc  ");
+  EXPECT_EQ(fmt::format("{0:^8}", reinterpret_cast<void*>(0xface)), " 0xface ");
+}
+
+TEST(format_test, fill) {
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{<5}"), 'c'), format_error,
+                   "invalid fill character '{'");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{<5}}"), 'c'), format_error,
+                   "invalid fill character '{'");
+  EXPECT_EQ(fmt::format("{0:*>4}", 42), "**42");
+  EXPECT_EQ(fmt::format("{0:*>5}", -42), "**-42");
+  EXPECT_EQ(fmt::format("{0:*>5}", 42u), "***42");
+  EXPECT_EQ(fmt::format("{0:*>5}", -42l), "**-42");
+  EXPECT_EQ(fmt::format("{0:*>5}", 42ul), "***42");
+  EXPECT_EQ(fmt::format("{0:*>5}", -42ll), "**-42");
+  EXPECT_EQ(fmt::format("{0:*>5}", 42ull), "***42");
+  EXPECT_EQ(fmt::format("{0:*>5}", -42.0), "**-42");
+  EXPECT_EQ(fmt::format("{0:*>5}", -42.0l), "**-42");
+  EXPECT_EQ(fmt::format("{0:*<5}", 'c'), "c****");
+  EXPECT_EQ(fmt::format("{0:*<5}", "abc"), "abc**");
+  EXPECT_EQ("**0xface",
+            fmt::format("{0:*>8}", reinterpret_cast<void*>(0xface)));
+  EXPECT_EQ(fmt::format("{:}=", "foo"), "foo=");
+  EXPECT_EQ(std::string("\0\0\0*", 4),
+            fmt::format(string_view("{:\0>4}", 6), '*'));
+  EXPECT_EQ(fmt::format("{0:ж>4}", 42), "жж42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:\x80\x80\x80\x80\x80>}"), 0),
+                   format_error, "invalid format specifier");
+}
+
+TEST(format_test, plus_sign) {
+  EXPECT_EQ(fmt::format("{0:+}", 42), "+42");
+  EXPECT_EQ(fmt::format("{0:+}", -42), "-42");
+  EXPECT_EQ(fmt::format("{0:+}", 42), "+42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:+}"), 42u), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:+}", 42l), "+42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:+}"), 42ul), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:+}", 42ll), "+42");
+#if FMT_USE_INT128
+  EXPECT_EQ(fmt::format("{0:+}", __int128_t(42)), "+42");
+#endif
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:+}"), 42ull), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:+}", 42.0), "+42");
+  EXPECT_EQ(fmt::format("{0:+}", 42.0l), "+42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:+}"), 'c'), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:+}"), "abc"), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0:+}"), reinterpret_cast<void*>(0x42)),
+      format_error, "invalid format specifier");
+}
+
+TEST(format_test, minus_sign) {
+  EXPECT_EQ(fmt::format("{0:-}", 42), "42");
+  EXPECT_EQ(fmt::format("{0:-}", -42), "-42");
+  EXPECT_EQ(fmt::format("{0:-}", 42), "42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:-}"), 42u), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:-}", 42l), "42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:-}"), 42ul), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:-}", 42ll), "42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:-}"), 42ull), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:-}", 42.0), "42");
+  EXPECT_EQ(fmt::format("{0:-}", 42.0l), "42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:-}"), 'c'), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:-}"), "abc"), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0:-}"), reinterpret_cast<void*>(0x42)),
+      format_error, "invalid format specifier");
+}
+
+TEST(format_test, space_sign) {
+  EXPECT_EQ(fmt::format("{0: }", 42), " 42");
+  EXPECT_EQ(fmt::format("{0: }", -42), "-42");
+  EXPECT_EQ(fmt::format("{0: }", 42), " 42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0: }"), 42u), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0: }", 42l), " 42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0: }"), 42ul), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0: }", 42ll), " 42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0: }"), 42ull), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0: }", 42.0), " 42");
+  EXPECT_EQ(fmt::format("{0: }", 42.0l), " 42");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0: }"), 'c'), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0: }"), "abc"), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0: }"), reinterpret_cast<void*>(0x42)),
+      format_error, "invalid format specifier");
+}
+
+TEST(format_test, hash_flag) {
+  EXPECT_EQ(fmt::format("{0:#}", 42), "42");
+  EXPECT_EQ(fmt::format("{0:#}", -42), "-42");
+  EXPECT_EQ(fmt::format("{0:#b}", 42), "0b101010");
+  EXPECT_EQ(fmt::format("{0:#B}", 42), "0B101010");
+  EXPECT_EQ(fmt::format("{0:#b}", -42), "-0b101010");
+  EXPECT_EQ(fmt::format("{0:#x}", 0x42), "0x42");
+  EXPECT_EQ(fmt::format("{0:#X}", 0x42), "0X42");
+  EXPECT_EQ(fmt::format("{0:#x}", -0x42), "-0x42");
+  EXPECT_EQ(fmt::format("{0:#o}", 0), "0");
+  EXPECT_EQ(fmt::format("{0:#o}", 042), "042");
+  EXPECT_EQ(fmt::format("{0:#o}", -042), "-042");
+  EXPECT_EQ(fmt::format("{0:#}", 42u), "42");
+  EXPECT_EQ(fmt::format("{0:#x}", 0x42u), "0x42");
+  EXPECT_EQ(fmt::format("{0:#o}", 042u), "042");
+
+  EXPECT_EQ(fmt::format("{0:#}", -42l), "-42");
+  EXPECT_EQ(fmt::format("{0:#x}", 0x42l), "0x42");
+  EXPECT_EQ(fmt::format("{0:#x}", -0x42l), "-0x42");
+  EXPECT_EQ(fmt::format("{0:#o}", 042l), "042");
+  EXPECT_EQ(fmt::format("{0:#o}", -042l), "-042");
+  EXPECT_EQ(fmt::format("{0:#}", 42ul), "42");
+  EXPECT_EQ(fmt::format("{0:#x}", 0x42ul), "0x42");
+  EXPECT_EQ(fmt::format("{0:#o}", 042ul), "042");
+
+  EXPECT_EQ(fmt::format("{0:#}", -42ll), "-42");
+  EXPECT_EQ(fmt::format("{0:#x}", 0x42ll), "0x42");
+  EXPECT_EQ(fmt::format("{0:#x}", -0x42ll), "-0x42");
+  EXPECT_EQ(fmt::format("{0:#o}", 042ll), "042");
+  EXPECT_EQ(fmt::format("{0:#o}", -042ll), "-042");
+  EXPECT_EQ(fmt::format("{0:#}", 42ull), "42");
+  EXPECT_EQ(fmt::format("{0:#x}", 0x42ull), "0x42");
+  EXPECT_EQ(fmt::format("{0:#o}", 042ull), "042");
+
+  EXPECT_EQ(fmt::format("{0:#}", -42.0), "-42.");
+  EXPECT_EQ(fmt::format("{0:#}", -42.0l), "-42.");
+  EXPECT_EQ(fmt::format("{:#.0e}", 42.0), "4.e+01");
+  EXPECT_EQ(fmt::format("{:#.0f}", 0.01), "0.");
+  EXPECT_EQ(fmt::format("{:#.2g}", 0.5), "0.50");
+  EXPECT_EQ(fmt::format("{:#.0f}", 0.5), "0.");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:#"), 'c'), format_error,
+                   "missing '}' in format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:#}"), 'c'), format_error,
+                   "invalid format specifier for char");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:#}"), "abc"), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0:#}"), reinterpret_cast<void*>(0x42)),
+      format_error, "invalid format specifier");
+}
+
+TEST(format_test, zero_flag) {
+  EXPECT_EQ(fmt::format("{0:0}", 42), "42");
+  EXPECT_EQ(fmt::format("{0:05}", -42), "-0042");
+  EXPECT_EQ(fmt::format("{0:05}", 42u), "00042");
+  EXPECT_EQ(fmt::format("{0:05}", -42l), "-0042");
+  EXPECT_EQ(fmt::format("{0:05}", 42ul), "00042");
+  EXPECT_EQ(fmt::format("{0:05}", -42ll), "-0042");
+  EXPECT_EQ(fmt::format("{0:05}", 42ull), "00042");
+  EXPECT_EQ(fmt::format("{0:07}", -42.0), "-000042");
+  EXPECT_EQ(fmt::format("{0:07}", -42.0l), "-000042");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:0"), 'c'), format_error,
+                   "missing '}' in format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:05}"), 'c'), format_error,
+                   "invalid format specifier for char");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:05}"), "abc"), format_error,
+                   "format specifier requires numeric argument");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0:05}"), reinterpret_cast<void*>(0x42)),
+      format_error, "format specifier requires numeric argument");
+}
+
+TEST(format_test, zero_flag_and_align) {
+  // If the 0 character and an align option both appear, the 0 character is
+  // ignored.
+  EXPECT_EQ(fmt::format("{:<05}", 42), "42   ");
+  EXPECT_EQ(fmt::format("{:<05}", -42), "-42  ");
+  EXPECT_EQ(fmt::format("{:^05}", 42), " 42  ");
+  EXPECT_EQ(fmt::format("{:^05}", -42), " -42 ");
+  EXPECT_EQ(fmt::format("{:>05}", 42), "   42");
+  EXPECT_EQ(fmt::format("{:>05}", -42), "  -42");
+}
+
+TEST(format_test, width) {
+  auto int_maxer = std::to_string(INT_MAX + 1u);
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:" + int_maxer), 0),
+                   format_error, "number is too big");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:" + int_maxer + "}"), 0),
+                   format_error, "number is too big");
+
+  EXPECT_EQ(fmt::format("{:4}", -42), " -42");
+  EXPECT_EQ(fmt::format("{:5}", 42u), "   42");
+  EXPECT_EQ(fmt::format("{:6}", -42l), "   -42");
+  EXPECT_EQ(fmt::format("{:7}", 42ul), "     42");
+  EXPECT_EQ(fmt::format("{:6}", -42ll), "   -42");
+  EXPECT_EQ(fmt::format("{:7}", 42ull), "     42");
+  EXPECT_EQ(fmt::format("{:8}", -1.23), "   -1.23");
+  EXPECT_EQ(fmt::format("{:9}", -1.23l), "    -1.23");
+  EXPECT_EQ(fmt::format("{:10}", reinterpret_cast<void*>(0xcafe)),
+            "    0xcafe");
+  EXPECT_EQ(fmt::format("{:11}", 'x'), "x          ");
+  EXPECT_EQ(fmt::format("{:12}", "str"), "str         ");
+  EXPECT_EQ(fmt::format("{:*^6}", "🤡"), "**🤡**");
+  EXPECT_EQ(fmt::format("{:*^8}", "你好"), "**你好**");
+  EXPECT_EQ(fmt::format("{:#6}", 42.0), "   42.");
+  EXPECT_EQ(fmt::format("{:6c}", static_cast<int>('x')), "x     ");
+  EXPECT_EQ(fmt::format("{:>06.0f}", 0.00884311), "     0");
+}
+
+TEST(format_test, runtime_width) {
+  auto int_maxer = std::to_string(INT_MAX + 1u);
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{" + int_maxer), 0),
+                   format_error, "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{" + int_maxer + "}"), 0),
+                   format_error, "argument not found");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{" + int_maxer + "}}"), 0),
+                   format_error, "argument not found");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{"), 0), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{}"), 0), format_error,
+                   "cannot switch from manual to automatic argument indexing");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{?}}"), 0), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0), format_error,
+                   "argument not found");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{0:}}"), 0), format_error,
+                   "invalid format string");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, -1), format_error,
+                   "negative width");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, (INT_MAX + 1u)),
+                   format_error, "number is too big");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, -1l), format_error,
+                   "negative width");
+  if (fmt::detail::const_check(sizeof(long) > sizeof(int))) {
+    long value = INT_MAX;
+    EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, (value + 1)),
+                     format_error, "number is too big");
+  }
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, (INT_MAX + 1ul)),
+                   format_error, "number is too big");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, '0'), format_error,
+                   "width is not integer");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:{1}}"), 0, 0.0), format_error,
+                   "width is not integer");
+
+  EXPECT_EQ(fmt::format("{0:{1}}", -42, 4), " -42");
+  EXPECT_EQ(fmt::format("{0:{1}}", 42u, 5), "   42");
+  EXPECT_EQ(fmt::format("{0:{1}}", -42l, 6), "   -42");
+  EXPECT_EQ(fmt::format("{0:{1}}", 42ul, 7), "     42");
+  EXPECT_EQ(fmt::format("{0:{1}}", -42ll, 6), "   -42");
+  EXPECT_EQ(fmt::format("{0:{1}}", 42ull, 7), "     42");
+  EXPECT_EQ(fmt::format("{0:{1}}", -1.23, 8), "   -1.23");
+  EXPECT_EQ(fmt::format("{0:{1}}", -1.23l, 9), "    -1.23");
+  EXPECT_EQ("    0xcafe",
+            fmt::format("{0:{1}}", reinterpret_cast<void*>(0xcafe), 10));
+  EXPECT_EQ(fmt::format("{0:{1}}", 'x', 11), "x          ");
+  EXPECT_EQ(fmt::format("{0:{1}}", "str", 12), "str         ");
+  EXPECT_EQ(fmt::format("{:{}}", 42, short(4)), "  42");
+}
+
+TEST(format_test, precision) {
+  char format_str[buffer_size];
+  safe_sprintf(format_str, "{0:.%u", UINT_MAX);
+  increment(format_str + 4);
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "number is too big");
+  size_t size = std::strlen(format_str);
+  format_str[size] = '}';
+  format_str[size + 1] = 0;
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "number is too big");
+
+  safe_sprintf(format_str, "{0:.%u", INT_MAX + 1u);
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "number is too big");
+  safe_sprintf(format_str, "{0:.%u}", INT_MAX + 1u);
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "number is too big");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:."), 0.0), format_error,
+                   "invalid precision");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.}"), 0.0), format_error,
+                   "invalid precision");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2"), 0), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2}"), 42), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2f}"), 42), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2}"), 42u), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2f}"), 42u), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2}"), 42l), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2f}"), 42l), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2}"), 42ul), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2f}"), 42ul), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2}"), 42ll), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2f}"), 42ll), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2}"), 42ull), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.2f}"), 42ull), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:3.0}"), 'x'), format_error,
+                   "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:.2}", 1.2345), "1.2");
+  EXPECT_EQ(fmt::format("{0:.2}", 1.2345l), "1.2");
+  EXPECT_EQ(fmt::format("{:.2}", 1.234e56), "1.2e+56");
+  EXPECT_EQ(fmt::format("{0:.3}", 1.1), "1.1");
+  EXPECT_EQ(fmt::format("{:.0e}", 1.0L), "1e+00");
+  EXPECT_EQ(fmt::format("{:9.1e}", 0.0), "  0.0e+00");
+  EXPECT_EQ(
+      fmt::format("{:.494}", 4.9406564584124654E-324),
+      "4.9406564584124654417656879286822137236505980261432476442558568250067550"
+      "727020875186529983636163599237979656469544571773092665671035593979639877"
+      "479601078187812630071319031140452784581716784898210368871863605699873072"
+      "305000638740915356498438731247339727316961514003171538539807412623856559"
+      "117102665855668676818703956031062493194527159149245532930545654440112748"
+      "012970999954193198940908041656332452475714786901472678015935523861155013"
+      "480352649347201937902681071074917033322268447533357208324319361e-324");
+  EXPECT_EQ(
+      fmt::format("{:.1074f}", 1.1125369292536e-308),
+      "0.0000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000111253692925360019747947051741965785554081512200979"
+      "355021686109411883779182127659725163430929750364498219730822952552570601"
+      "152163505899912777129583674906301179059298598412303893909188340988729019"
+      "014361467448914817838555156840459458527907308695109202499990850735085304"
+      "478476991912072201449236975063640913461919914396877093174125167509869762"
+      "482369631100360266123742648159508919592746619553246586039571522788247697"
+      "156360766271842991667238355464496455107749716934387136380536472531224398"
+      "559833794807213172371254492216255558078524900147957309382830827524104234"
+      "530961756787819847850302379672357738807808384667004752163416921762619527"
+      "462847642037420991432005657440259928195996762610375541867198059294212446"
+      "81962777939941034720757232455434770912461317493580281734466552734375");
+
+  std::string outputs[] = {
+      "-0X1.41FE3FFE71C9E000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000P+127",
+      "-0XA.0FF1FFF38E4F0000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000P+124"};
+  EXPECT_THAT(outputs,
+              testing::Contains(fmt::format("{:.838A}", -2.14001164E+38)));
+
+  if (std::numeric_limits<long double>::digits == 64) {
+    auto ld = (std::numeric_limits<long double>::min)();
+    EXPECT_EQ(fmt::format("{:.0}", ld), "3e-4932");
+    EXPECT_EQ(
+        fmt::format("{:0g}", std::numeric_limits<long double>::denorm_min()),
+        "3.6452e-4951");
+  }
+
+  EXPECT_EQ(fmt::format("{:#.0f}", 123.0), "123.");
+  EXPECT_EQ(fmt::format("{:.02f}", 1.234), "1.23");
+  EXPECT_EQ(fmt::format("{:.1g}", 0.001), "0.001");
+  EXPECT_EQ(fmt::format("{}", 1019666432.0f), "1019666400");
+  EXPECT_EQ(fmt::format("{:.0e}", 9.5), "1e+01");
+  EXPECT_EQ(fmt::format("{:.1e}", 1e-34), "1.0e-34");
+
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0:.2}"), reinterpret_cast<void*>(0xcafe)),
+      format_error, "invalid format specifier");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{0:.2f}"), reinterpret_cast<void*>(0xcafe)),
+      format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:.{}e}"), 42.0,
+                                     fmt::detail::max_value<int>()),
+                   format_error, "number is too big");
+  EXPECT_THROW_MSG(
+      (void)fmt::format("{:.2147483646f}", -2.2121295195081227E+304),
+      format_error, "number is too big");
+
+  EXPECT_EQ(fmt::format("{0:.2}", "str"), "st");
+  EXPECT_EQ(fmt::format("{0:.5}", "вожыкі"), "вожык");
+  EXPECT_EQ(fmt::format("{0:.6}", "123456\xad"), "123456");
+}
+
+TEST(xchar_test, utf8_precision) {
+  auto result = fmt::format("{:.4}", "caf\u00e9s");  // cafés
+  EXPECT_EQ(fmt::detail::compute_width(result), 4);
+  EXPECT_EQ(result, "caf\u00e9");
+}
+
+TEST(format_test, runtime_precision) {
+  char format_str[buffer_size];
+  safe_sprintf(format_str, "{0:.{%u", UINT_MAX);
+  increment(format_str + 5);
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "invalid format string");
+  size_t size = std::strlen(format_str);
+  format_str[size] = '}';
+  format_str[size + 1] = 0;
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "argument not found");
+  format_str[size + 1] = '}';
+  format_str[size + 2] = 0;
+  EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), 0.0), format_error,
+                   "argument not found");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{"), 0.0), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{}"), 0.0), format_error,
+                   "cannot switch from manual to automatic argument indexing");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{?}}"), 0.0), format_error,
+                   "invalid format string");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}"), 0, 0), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0), format_error,
+                   "argument not found");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{0:}}"), 0.0), format_error,
+                   "invalid format string");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, -1),
+                   format_error, "negative precision");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, (INT_MAX + 1u)),
+                   format_error, "number is too big");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, -1l),
+                   format_error, "negative precision");
+  if (fmt::detail::const_check(sizeof(long) > sizeof(int))) {
+    long value = INT_MAX;
+    EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, (value + 1)),
+                     format_error, "number is too big");
+  }
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, (INT_MAX + 1ul)),
+                   format_error, "number is too big");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, '0'),
+                   format_error, "precision is not integer");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 0.0, 0.0),
+                   format_error, "precision is not integer");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 42, 2), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"), 42, 2), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 42u, 2), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"), 42u, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 42l, 2), format_error,
+                   "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"), 42l, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 42ul, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"), 42ul, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 42ll, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"), 42ll, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"), 42ull, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"), 42ull, 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:3.{1}}"), 'x', 0),
+                   format_error, "invalid format specifier");
+  EXPECT_EQ(fmt::format("{0:.{1}}", 1.2345, 2), "1.2");
+  EXPECT_EQ(fmt::format("{1:.{0}}", 2, 1.2345l), "1.2");
+
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}}"),
+                                     reinterpret_cast<void*>(0xcafe), 2),
+                   format_error, "invalid format specifier");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:.{1}f}"),
+                                     reinterpret_cast<void*>(0xcafe), 2),
+                   format_error, "invalid format specifier");
+
+  EXPECT_EQ(fmt::format("{0:.{1}}", "str", 2), "st");
+}
+
+TEST(format_test, format_bool) {
+  EXPECT_EQ(fmt::format("{}", true), "true");
+  EXPECT_EQ(fmt::format("{}", false), "false");
+  EXPECT_EQ(fmt::format("{:d}", true), "1");
+  EXPECT_EQ(fmt::format("{:5}", true), "true ");
+  EXPECT_EQ(fmt::format("{:s}", true), "true");
+  EXPECT_EQ(fmt::format("{:s}", false), "false");
+  EXPECT_EQ(fmt::format("{:6s}", false), "false ");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:c}"), false), format_error,
+                   "invalid format specifier");
+}
+
+TEST(format_test, format_short) {
+  short s = 42;
+  EXPECT_EQ(fmt::format("{0:d}", s), "42");
+  unsigned short us = 42;
+  EXPECT_EQ(fmt::format("{0:d}", us), "42");
+}
+
+template <typename T>
+void check_unknown_types(const T& value, const char* types, const char*) {
+  char format_str[buffer_size];
+  const char* special = ".0123456789L?}";
+  for (int i = CHAR_MIN; i <= CHAR_MAX; ++i) {
+    char c = static_cast<char>(i);
+    if (std::strchr(types, c) || std::strchr(special, c) || !c) continue;
+    safe_sprintf(format_str, "{0:10%c}", c);
+    const char* message = "invalid format specifier";
+    EXPECT_THROW_MSG((void)fmt::format(runtime(format_str), value),
+                     format_error, message)
+        << format_str << " " << message;
+  }
+}
+
+TEST(format_test, format_int) {
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{0:v"), 42), format_error,
+                   "invalid format specifier");
+  check_unknown_types(42, "bBdoxXnLc", "integer");
+  EXPECT_EQ(fmt::format("{:c}", static_cast<int>('x')), "x");
+}
+
+TEST(format_test, format_bin) {
+  EXPECT_EQ(fmt::format("{0:b}", 0), "0");
+  EXPECT_EQ(fmt::format("{0:b}", 42), "101010");
+  EXPECT_EQ(fmt::format("{0:b}", 42u), "101010");
+  EXPECT_EQ(fmt::format("{0:b}", -42), "-101010");
+  EXPECT_EQ(fmt::format("{0:b}", 12345), "11000000111001");
+  EXPECT_EQ(fmt::format("{0:b}", 0x12345678), "10010001101000101011001111000");
+  EXPECT_EQ("10010000101010111100110111101111",
+            fmt::format("{0:b}", 0x90ABCDEF));
+  EXPECT_EQ("11111111111111111111111111111111",
+            fmt::format("{0:b}", max_value<uint32_t>()));
+}
+
+#if FMT_USE_INT128
+constexpr auto int128_max = static_cast<__int128_t>(
+    (static_cast<__uint128_t>(1) << ((__SIZEOF_INT128__ * CHAR_BIT) - 1)) - 1);
+constexpr auto int128_min = -int128_max - 1;
+
+constexpr auto uint128_max = ~static_cast<__uint128_t>(0);
+#endif
+
+TEST(format_test, format_dec) {
+  EXPECT_EQ(fmt::format("{0}", 0), "0");
+  EXPECT_EQ(fmt::format("{0}", 42), "42");
+  EXPECT_EQ(fmt::format("{:}>", 42), "42>");
+  EXPECT_EQ(fmt::format("{0:d}", 42), "42");
+  EXPECT_EQ(fmt::format("{0}", 42u), "42");
+  EXPECT_EQ(fmt::format("{0}", -42), "-42");
+  EXPECT_EQ(fmt::format("{0}", 12345), "12345");
+  EXPECT_EQ(fmt::format("{0}", 67890), "67890");
+#if FMT_USE_INT128
+  EXPECT_EQ(fmt::format("{0}", static_cast<__int128_t>(0)), "0");
+  EXPECT_EQ(fmt::format("{0}", static_cast<__uint128_t>(0)), "0");
+  EXPECT_EQ("9223372036854775808",
+            fmt::format("{0}", static_cast<__int128_t>(INT64_MAX) + 1));
+  EXPECT_EQ("-9223372036854775809",
+            fmt::format("{0}", static_cast<__int128_t>(INT64_MIN) - 1));
+  EXPECT_EQ("18446744073709551616",
+            fmt::format("{0}", static_cast<__int128_t>(UINT64_MAX) + 1));
+  EXPECT_EQ("170141183460469231731687303715884105727",
+            fmt::format("{0}", int128_max));
+  EXPECT_EQ("-170141183460469231731687303715884105728",
+            fmt::format("{0}", int128_min));
+  EXPECT_EQ("340282366920938463463374607431768211455",
+            fmt::format("{0}", uint128_max));
+#endif
+
+  char buffer[buffer_size];
+  safe_sprintf(buffer, "%d", INT_MIN);
+  EXPECT_EQ(buffer, fmt::format("{0}", INT_MIN));
+  safe_sprintf(buffer, "%d", INT_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0}", INT_MAX));
+  safe_sprintf(buffer, "%u", UINT_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0}", UINT_MAX));
+  safe_sprintf(buffer, "%ld", 0 - static_cast<unsigned long>(LONG_MIN));
+  EXPECT_EQ(buffer, fmt::format("{0}", LONG_MIN));
+  safe_sprintf(buffer, "%ld", LONG_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0}", LONG_MAX));
+  safe_sprintf(buffer, "%lu", ULONG_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0}", ULONG_MAX));
+}
+
+TEST(format_test, format_hex) {
+  EXPECT_EQ(fmt::format("{0:x}", 0), "0");
+  EXPECT_EQ(fmt::format("{0:x}", 0x42), "42");
+  EXPECT_EQ(fmt::format("{0:x}", 0x42u), "42");
+  EXPECT_EQ(fmt::format("{0:x}", -0x42), "-42");
+  EXPECT_EQ(fmt::format("{0:x}", 0x12345678), "12345678");
+  EXPECT_EQ(fmt::format("{0:x}", 0x90abcdef), "90abcdef");
+  EXPECT_EQ(fmt::format("{0:X}", 0x12345678), "12345678");
+  EXPECT_EQ(fmt::format("{0:X}", 0x90ABCDEF), "90ABCDEF");
+#if FMT_USE_INT128
+  EXPECT_EQ(fmt::format("{0:x}", static_cast<__int128_t>(0)), "0");
+  EXPECT_EQ(fmt::format("{0:x}", static_cast<__uint128_t>(0)), "0");
+  EXPECT_EQ("8000000000000000",
+            fmt::format("{0:x}", static_cast<__int128_t>(INT64_MAX) + 1));
+  EXPECT_EQ("-8000000000000001",
+            fmt::format("{0:x}", static_cast<__int128_t>(INT64_MIN) - 1));
+  EXPECT_EQ("10000000000000000",
+            fmt::format("{0:x}", static_cast<__int128_t>(UINT64_MAX) + 1));
+  EXPECT_EQ("7fffffffffffffffffffffffffffffff",
+            fmt::format("{0:x}", int128_max));
+  EXPECT_EQ("-80000000000000000000000000000000",
+            fmt::format("{0:x}", int128_min));
+  EXPECT_EQ("ffffffffffffffffffffffffffffffff",
+            fmt::format("{0:x}", uint128_max));
+#endif
+
+  char buffer[buffer_size];
+  safe_sprintf(buffer, "-%x", 0 - static_cast<unsigned>(INT_MIN));
+  EXPECT_EQ(buffer, fmt::format("{0:x}", INT_MIN));
+  safe_sprintf(buffer, "%x", INT_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:x}", INT_MAX));
+  safe_sprintf(buffer, "%x", UINT_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:x}", UINT_MAX));
+  safe_sprintf(buffer, "-%lx", 0 - static_cast<unsigned long>(LONG_MIN));
+  EXPECT_EQ(buffer, fmt::format("{0:x}", LONG_MIN));
+  safe_sprintf(buffer, "%lx", LONG_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:x}", LONG_MAX));
+  safe_sprintf(buffer, "%lx", ULONG_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:x}", ULONG_MAX));
+}
+
+TEST(format_test, format_oct) {
+  EXPECT_EQ(fmt::format("{0:o}", 0), "0");
+  EXPECT_EQ(fmt::format("{0:o}", 042), "42");
+  EXPECT_EQ(fmt::format("{0:o}", 042u), "42");
+  EXPECT_EQ(fmt::format("{0:o}", -042), "-42");
+  EXPECT_EQ(fmt::format("{0:o}", 012345670), "12345670");
+#if FMT_USE_INT128
+  EXPECT_EQ(fmt::format("{0:o}", static_cast<__int128_t>(0)), "0");
+  EXPECT_EQ(fmt::format("{0:o}", static_cast<__uint128_t>(0)), "0");
+  EXPECT_EQ("1000000000000000000000",
+            fmt::format("{0:o}", static_cast<__int128_t>(INT64_MAX) + 1));
+  EXPECT_EQ("-1000000000000000000001",
+            fmt::format("{0:o}", static_cast<__int128_t>(INT64_MIN) - 1));
+  EXPECT_EQ("2000000000000000000000",
+            fmt::format("{0:o}", static_cast<__int128_t>(UINT64_MAX) + 1));
+  EXPECT_EQ("1777777777777777777777777777777777777777777",
+            fmt::format("{0:o}", int128_max));
+  EXPECT_EQ("-2000000000000000000000000000000000000000000",
+            fmt::format("{0:o}", int128_min));
+  EXPECT_EQ("3777777777777777777777777777777777777777777",
+            fmt::format("{0:o}", uint128_max));
+#endif
+
+  char buffer[buffer_size];
+  safe_sprintf(buffer, "-%o", 0 - static_cast<unsigned>(INT_MIN));
+  EXPECT_EQ(buffer, fmt::format("{0:o}", INT_MIN));
+  safe_sprintf(buffer, "%o", INT_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:o}", INT_MAX));
+  safe_sprintf(buffer, "%o", UINT_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:o}", UINT_MAX));
+  safe_sprintf(buffer, "-%lo", 0 - static_cast<unsigned long>(LONG_MIN));
+  EXPECT_EQ(buffer, fmt::format("{0:o}", LONG_MIN));
+  safe_sprintf(buffer, "%lo", LONG_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:o}", LONG_MAX));
+  safe_sprintf(buffer, "%lo", ULONG_MAX);
+  EXPECT_EQ(buffer, fmt::format("{0:o}", ULONG_MAX));
+}
+
+TEST(format_test, format_int_locale) {
+  EXPECT_EQ(fmt::format("{:L}", 1234), "1234");
+}
+
+TEST(format_test, format_float) {
+  EXPECT_EQ(fmt::format("{}", 0.0f), "0");
+  EXPECT_EQ(fmt::format("{0:f}", 392.5f), "392.500000");
+}
+
+TEST(format_test, format_double) {
+  EXPECT_EQ(fmt::format("{}", 0.0), "0");
+  check_unknown_types(1.2, "eEfFgGaAnL%", "double");
+  EXPECT_EQ(fmt::format("{:}", 0.0), "0");
+  EXPECT_EQ(fmt::format("{:f}", 0.0), "0.000000");
+  EXPECT_EQ(fmt::format("{:g}", 0.0), "0");
+  EXPECT_EQ(fmt::format("{:}", 392.65), "392.65");
+  EXPECT_EQ(fmt::format("{:g}", 392.65), "392.65");
+  EXPECT_EQ(fmt::format("{:G}", 392.65), "392.65");
+  EXPECT_EQ(fmt::format("{:g}", 4.9014e6), "4.9014e+06");
+  EXPECT_EQ(fmt::format("{:f}", 392.65), "392.650000");
+  EXPECT_EQ(fmt::format("{:F}", 392.65), "392.650000");
+  EXPECT_EQ(fmt::format("{:L}", 42.0), "42");
+  EXPECT_EQ(fmt::format("{:24a}", 4.2f), "           0x1.0cccccp+2");
+  EXPECT_EQ(fmt::format("{:24a}", 4.2), "    0x1.0cccccccccccdp+2");
+  EXPECT_EQ(fmt::format("{:<24a}", 4.2), "0x1.0cccccccccccdp+2    ");
+  EXPECT_EQ(fmt::format("{0:e}", 392.65), "3.926500e+02");
+  EXPECT_EQ(fmt::format("{0:E}", 392.65), "3.926500E+02");
+  EXPECT_EQ(fmt::format("{0:+010.4g}", 392.65), "+0000392.6");
+
+#if FMT_CPLUSPLUS >= 201703L
+  double xd = 0x1.ffffffffffp+2;
+  EXPECT_EQ(fmt::format("{:.10a}", xd), "0x1.ffffffffffp+2");
+  EXPECT_EQ(fmt::format("{:.9a}", xd), "0x2.000000000p+2");
+
+  if (std::numeric_limits<long double>::digits == 64) {
+    auto ld = 0xf.ffffffffffp-3l;
+    EXPECT_EQ(fmt::format("{:a}", ld), "0xf.ffffffffffp-3");
+    EXPECT_EQ(fmt::format("{:.10a}", ld), "0xf.ffffffffffp-3");
+    EXPECT_EQ(fmt::format("{:.9a}", ld), "0x1.000000000p+1");
+  }
+#endif
+
+  if (fmt::detail::const_check(std::numeric_limits<double>::is_iec559)) {
+    double d = (std::numeric_limits<double>::min)();
+    EXPECT_EQ(fmt::format("{:a}", d), "0x1p-1022");
+    EXPECT_EQ(fmt::format("{:#a}", d), "0x1.p-1022");
+
+    d = (std::numeric_limits<double>::max)();
+    EXPECT_EQ(fmt::format("{:a}", d), "0x1.fffffffffffffp+1023");
+
+    d = std::numeric_limits<double>::denorm_min();
+    EXPECT_EQ(fmt::format("{:a}", d), "0x0.0000000000001p-1022");
+  }
+
+  if (std::numeric_limits<long double>::digits == 64) {
+    auto ld = (std::numeric_limits<long double>::min)();
+    EXPECT_EQ(fmt::format("{:a}", ld), "0x8p-16385");
+
+    ld = (std::numeric_limits<long double>::max)();
+    EXPECT_EQ(fmt::format("{:a}", ld), "0xf.fffffffffffffffp+16380");
+
+    ld = std::numeric_limits<long double>::denorm_min();
+    EXPECT_EQ(fmt::format("{:a}", ld), "0x0.000000000000001p-16382");
+  }
+
+  EXPECT_EQ(fmt::format("{:.10a}", 4.2), "0x1.0ccccccccdp+2");
+
+  EXPECT_EQ(fmt::format("{:a}", -42.0), "-0x1.5p+5");
+  EXPECT_EQ(fmt::format("{:A}", -42.0), "-0X1.5P+5");
+
+  EXPECT_EQ(fmt::format("{:f}", 9223372036854775807.0),
+            "9223372036854775808.000000");
+}
+
+TEST(format_test, precision_rounding) {
+  EXPECT_EQ(fmt::format("{:.0f}", 0.0), "0");
+  EXPECT_EQ(fmt::format("{:.0f}", 0.01), "0");
+  EXPECT_EQ(fmt::format("{:.0f}", 0.1), "0");
+  EXPECT_EQ(fmt::format("{:.3f}", 0.00049), "0.000");
+  EXPECT_EQ(fmt::format("{:.3f}", 0.0005), "0.001");
+  EXPECT_EQ(fmt::format("{:.3f}", 0.00149), "0.001");
+  EXPECT_EQ(fmt::format("{:.3f}", 0.0015), "0.002");
+  EXPECT_EQ(fmt::format("{:.3f}", 0.9999), "1.000");
+  EXPECT_EQ(fmt::format("{:.3}", 0.00123), "0.00123");
+  EXPECT_EQ(fmt::format("{:.16g}", 0.1), "0.1");
+  EXPECT_EQ(fmt::format("{:.0}", 1.0), "1");
+  EXPECT_EQ("225.51575035152063720",
+            fmt::format("{:.17f}", 225.51575035152064));
+  EXPECT_EQ(fmt::format("{:.1f}", -761519619559038.2), "-761519619559038.2");
+  EXPECT_EQ("1.9156918820264798e-56",
+            fmt::format("{}", 1.9156918820264798e-56));
+  EXPECT_EQ(fmt::format("{:.4f}", 7.2809479766055470e-15), "0.0000");
+}
+
+TEST(format_test, prettify_float) {
+  EXPECT_EQ(fmt::format("{}", 1e-4), "0.0001");
+  EXPECT_EQ(fmt::format("{}", 1e-5), "1e-05");
+  EXPECT_EQ(fmt::format("{}", 1e15), "1000000000000000");
+  EXPECT_EQ(fmt::format("{}", 1e16), "1e+16");
+  EXPECT_EQ(fmt::format("{}", 9.999e-5), "9.999e-05");
+  EXPECT_EQ(fmt::format("{}", 1e10), "10000000000");
+  EXPECT_EQ(fmt::format("{}", 1e11), "100000000000");
+  EXPECT_EQ(fmt::format("{}", 1234e7), "12340000000");
+  EXPECT_EQ(fmt::format("{}", 1234e-2), "12.34");
+  EXPECT_EQ(fmt::format("{}", 1234e-6), "0.001234");
+  EXPECT_EQ(fmt::format("{}", 0.1f), "0.1");
+  EXPECT_EQ(fmt::format("{}", 1.35631564e-19f), "1.3563156e-19");
+}
+
+TEST(format_test, format_nan) {
+  double nan = std::numeric_limits<double>::quiet_NaN();
+  EXPECT_EQ(fmt::format("{}", nan), "nan");
+  EXPECT_EQ(fmt::format("{:+}", nan), "+nan");
+  EXPECT_EQ(fmt::format("{:+06}", nan), "  +nan");
+  EXPECT_EQ(fmt::format("{:<+06}", nan), "+nan  ");
+  EXPECT_EQ(fmt::format("{:^+06}", nan), " +nan ");
+  EXPECT_EQ(fmt::format("{:>+06}", nan), "  +nan");
+  if (std::signbit(-nan)) {
+    EXPECT_EQ(fmt::format("{}", -nan), "-nan");
+    EXPECT_EQ(fmt::format("{:+06}", -nan), "  -nan");
+  } else {
+    fmt::print("Warning: compiler doesn't handle negative NaN correctly");
+  }
+  EXPECT_EQ(fmt::format("{: }", nan), " nan");
+  EXPECT_EQ(fmt::format("{:F}", nan), "NAN");
+  EXPECT_EQ(fmt::format("{:<7}", nan), "nan    ");
+  EXPECT_EQ(fmt::format("{:^7}", nan), "  nan  ");
+  EXPECT_EQ(fmt::format("{:>7}", nan), "    nan");
+}
+
+TEST(format_test, format_infinity) {
+  double inf = std::numeric_limits<double>::infinity();
+  EXPECT_EQ(fmt::format("{}", inf), "inf");
+  EXPECT_EQ(fmt::format("{:+}", inf), "+inf");
+  EXPECT_EQ(fmt::format("{}", -inf), "-inf");
+  EXPECT_EQ(fmt::format("{:+06}", inf), "  +inf");
+  EXPECT_EQ(fmt::format("{:+06}", -inf), "  -inf");
+  EXPECT_EQ(fmt::format("{:<+06}", inf), "+inf  ");
+  EXPECT_EQ(fmt::format("{:^+06}", inf), " +inf ");
+  EXPECT_EQ(fmt::format("{:>+06}", inf), "  +inf");
+  EXPECT_EQ(fmt::format("{: }", inf), " inf");
+  EXPECT_EQ(fmt::format("{:F}", inf), "INF");
+  EXPECT_EQ(fmt::format("{:<7}", inf), "inf    ");
+  EXPECT_EQ(fmt::format("{:^7}", inf), "  inf  ");
+  EXPECT_EQ(fmt::format("{:>7}", inf), "    inf");
+}
+
+TEST(format_test, format_long_double) {
+  EXPECT_EQ(fmt::format("{0:}", 0.0l), "0");
+  EXPECT_EQ(fmt::format("{0:f}", 0.0l), "0.000000");
+  EXPECT_EQ(fmt::format("{:.1f}", 0.000000001l), "0.0");
+  EXPECT_EQ(fmt::format("{:.2f}", 0.099l), "0.10");
+  EXPECT_EQ(fmt::format("{0:}", 392.65l), "392.65");
+  EXPECT_EQ(fmt::format("{0:g}", 392.65l), "392.65");
+  EXPECT_EQ(fmt::format("{0:G}", 392.65l), "392.65");
+  EXPECT_EQ(fmt::format("{0:f}", 392.65l), "392.650000");
+  EXPECT_EQ(fmt::format("{0:F}", 392.65l), "392.650000");
+  char buffer[buffer_size];
+  safe_sprintf(buffer, "%Le", 392.65l);
+  EXPECT_EQ(buffer, fmt::format("{0:e}", 392.65l));
+  EXPECT_EQ(fmt::format("{0:+010.4g}", 392.64l), "+0000392.6");
+
+  auto ld = 3.31l;
+  if (fmt::detail::is_double_double<decltype(ld)>::value) {
+    safe_sprintf(buffer, "%a", static_cast<double>(ld));
+    EXPECT_EQ(buffer, fmt::format("{:a}", ld));
+  } else if (std::numeric_limits<long double>::digits == 64) {
+    EXPECT_EQ(fmt::format("{:a}", ld), "0xd.3d70a3d70a3d70ap-2");
+  }
+}
+
+TEST(format_test, format_char) {
+  const char types[] = "cbBdoxX";
+  check_unknown_types('a', types, "char");
+  EXPECT_EQ(fmt::format("{0}", 'a'), "a");
+  EXPECT_EQ(fmt::format("{0:c}", 'z'), "z");
+  int n = 'x';
+  for (const char* type = types + 1; *type; ++type) {
+    std::string format_str = fmt::format("{{:{}}}", *type);
+    EXPECT_EQ(fmt::format(runtime(format_str), n),
+              fmt::format(runtime(format_str), 'x'))
+        << format_str;
+  }
+  EXPECT_EQ(fmt::format("{:02X}", n), fmt::format("{:02X}", 'x'));
+
+  EXPECT_EQ(fmt::format("{}", '\n'), "\n");
+  EXPECT_EQ(fmt::format("{:?}", '\n'), "'\\n'");
+  EXPECT_EQ(fmt::format("{:x}", '\xff'), "ff");
+}
+
+TEST(format_test, format_volatile_char) {
+  volatile char c = 'x';
+  EXPECT_EQ(fmt::format("{}", c), "x");
+}
+
+TEST(format_test, format_unsigned_char) {
+  EXPECT_EQ(fmt::format("{}", static_cast<unsigned char>(42)), "42");
+  EXPECT_EQ(fmt::format("{}", static_cast<uint8_t>(42)), "42");
+}
+
+TEST(format_test, format_cstring) {
+  check_unknown_types("test", "sp", "string");
+  EXPECT_EQ(fmt::format("{0}", "test"), "test");
+  EXPECT_EQ(fmt::format("{0:s}", "test"), "test");
+  char nonconst[] = "nonconst";
+  EXPECT_EQ(fmt::format("{0}", nonconst), "nonconst");
+  auto nullstr = static_cast<const char*>(nullptr);
+  EXPECT_THROW_MSG((void)fmt::format("{}", nullstr), format_error,
+                   "string pointer is null");
+  EXPECT_THROW_MSG((void)fmt::format("{:s}", nullstr), format_error,
+                   "string pointer is null");
+}
+
+void function_pointer_test(int, double, std::string) {}
+
+TEST(format_test, format_pointer) {
+  check_unknown_types(reinterpret_cast<void*>(0x1234), "p", "pointer");
+  EXPECT_EQ(fmt::format("{0}", static_cast<void*>(nullptr)), "0x0");
+  EXPECT_EQ(fmt::format("{0}", reinterpret_cast<void*>(0x1234)), "0x1234");
+  EXPECT_EQ(fmt::format("{0:p}", reinterpret_cast<void*>(0x1234)), "0x1234");
+  // On CHERI (or other fat-pointer) systems, the size of a pointer is greater
+  // than the size an integer that can hold a virtual address.  There is no
+  // portable address-as-an-integer type (yet) in C++, so we use `size_t` as
+  // the closest equivalent for now.
+  EXPECT_EQ("0x" + std::string(sizeof(size_t) * CHAR_BIT / 4, 'f'),
+            fmt::format("{0}", reinterpret_cast<void*>(~uintptr_t())));
+  EXPECT_EQ("0x1234",
+            fmt::format("{}", fmt::ptr(reinterpret_cast<int*>(0x1234))));
+  std::unique_ptr<int> up(new int(1));
+  EXPECT_EQ(fmt::format("{}", fmt::ptr(up.get())),
+            fmt::format("{}", fmt::ptr(up)));
+  struct custom_deleter {
+    void operator()(int* p) const { delete p; }
+  };
+  std::unique_ptr<int, custom_deleter> upcd(new int(1));
+  EXPECT_EQ(fmt::format("{}", fmt::ptr(upcd.get())),
+            fmt::format("{}", fmt::ptr(upcd)));
+  std::shared_ptr<int> sp(new int(1));
+  EXPECT_EQ(fmt::format("{}", fmt::ptr(sp.get())),
+            fmt::format("{}", fmt::ptr(sp)));
+  EXPECT_EQ(fmt::format("{}", fmt::detail::bit_cast<const void*>(
+                                  &function_pointer_test)),
+            fmt::format("{}", fmt::ptr(function_pointer_test)));
+  EXPECT_EQ(fmt::format("{}", nullptr), "0x0");
+}
+
+TEST(format_test, write_uintptr_fallback) {
+  // Test that formatting a pointer by converting it to uint128_fallback works.
+  // This is needed to support systems without uintptr_t.
+  auto s = std::string();
+  fmt::detail::write_ptr<char>(
+      std::back_inserter(s),
+      fmt::detail::bit_cast<fmt::detail::uint128_fallback>(
+          reinterpret_cast<void*>(0xface)),
+      nullptr);
+  EXPECT_EQ(s, "0xface");
+}
+
+enum class color { red, green, blue };
+
+namespace test_ns {
+enum class color { red, green, blue };
+using fmt::enums::format_as;
+}  // namespace test_ns
+
+TEST(format_test, format_enum_class) {
+  EXPECT_EQ(fmt::format("{}", fmt::underlying(color::red)), "0");
+  EXPECT_EQ(fmt::format("{}", test_ns::color::red), "0");
+}
+
+TEST(format_test, format_string) {
+  EXPECT_EQ(fmt::format("{0}", std::string("test")), "test");
+  EXPECT_EQ(fmt::format("{0}", std::string("test")), "test");
+  EXPECT_EQ(fmt::format("{:?}", std::string("test")), "\"test\"");
+  EXPECT_EQ(fmt::format("{:*^10?}", std::string("test")), "**\"test\"**");
+  EXPECT_EQ(fmt::format("{:?}", std::string("\test")), "\"\\test\"");
+  EXPECT_THROW((void)fmt::format(fmt::runtime("{:x}"), std::string("test")),
+               fmt::format_error);
+}
+
+TEST(format_test, format_string_view) {
+  EXPECT_EQ(fmt::format("{}", string_view("test")), "test");
+  EXPECT_EQ(fmt::format("{:?}", string_view("t\nst")), "\"t\\nst\"");
+  EXPECT_EQ(fmt::format("{}", string_view()), "");
+}
+
+#ifdef FMT_USE_STRING_VIEW
+struct string_viewable {};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<string_viewable> : formatter<std::string_view> {
+  auto format(string_viewable, format_context& ctx) -> decltype(ctx.out()) {
+    return formatter<std::string_view>::format("foo", ctx);
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(format_test, format_std_string_view) {
+  EXPECT_EQ(fmt::format("{}", std::string_view("test")), "test");
+  EXPECT_EQ(fmt::format("{}", string_viewable()), "foo");
+}
+
+struct explicitly_convertible_to_std_string_view {
+  explicit operator std::string_view() const { return "foo"; }
+};
+
+template <>
+struct fmt::formatter<explicitly_convertible_to_std_string_view>
+    : formatter<std::string_view> {
+  auto format(explicitly_convertible_to_std_string_view v, format_context& ctx)
+      -> decltype(ctx.out()) {
+    return fmt::format_to(ctx.out(), "'{}'", std::string_view(v));
+  }
+};
+
+TEST(format_test, format_explicitly_convertible_to_std_string_view) {
+  EXPECT_EQ("'foo'",
+            fmt::format("{}", explicitly_convertible_to_std_string_view()));
+}
+#endif
+
+class Answer {};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<date> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    if (it != ctx.end() && *it == 'd') ++it;
+    return it;
+  }
+
+  auto format(const date& d, format_context& ctx) -> decltype(ctx.out()) {
+    // Namespace-qualify to avoid ambiguity with std::format_to.
+    fmt::format_to(ctx.out(), "{}-{}-{}", d.year(), d.month(), d.day());
+    return ctx.out();
+  }
+};
+
+template <> struct formatter<Answer> : formatter<int> {
+  template <typename FormatContext>
+  auto format(Answer, FormatContext& ctx) -> decltype(ctx.out()) {
+    return formatter<int>::format(42, ctx);
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(format_test, format_custom) {
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:s}"), date(2012, 12, 9)),
+                   format_error, "unknown format specifier");
+  EXPECT_EQ(fmt::format("{0}", Answer()), "42");
+  EXPECT_EQ(fmt::format("{:04}", Answer()), "0042");
+}
+
+TEST(format_test, format_to_custom) {
+  char buf[10] = {};
+  auto end = fmt::format_to(buf, "{}", Answer());
+  EXPECT_EQ(end, buf + 2);
+  EXPECT_STREQ(buf, "42");
+}
+
+TEST(format_test, format_string_from_speed_test) {
+  EXPECT_EQ("1.2340000000:0042:+3.13:str:0x3e8:X:%",
+            fmt::format("{0:0.10f}:{1:04}:{2:+g}:{3}:{4}:{5}:%", 1.234, 42,
+                        3.13, "str", reinterpret_cast<void*>(1000), 'X'));
+}
+
+TEST(format_test, format_examples) {
+  std::string message = fmt::format("The answer is {}", 42);
+  EXPECT_EQ("The answer is 42", message);
+
+  EXPECT_EQ(fmt::format("{}", 42), "42");
+
+  memory_buffer out;
+  fmt::format_to(std::back_inserter(out), "The answer is {}.", 42);
+  EXPECT_EQ("The answer is 42.", to_string(out));
+
+  const char* filename = "nonexistent";
+  FILE* ftest = safe_fopen(filename, "r");
+  if (ftest) fclose(ftest);
+  int error_code = errno;
+  EXPECT_TRUE(ftest == nullptr);
+  EXPECT_SYSTEM_ERROR(
+      {
+        FILE* f = safe_fopen(filename, "r");
+        if (!f)
+          throw fmt::system_error(errno, "Cannot open file '{}'", filename);
+        fclose(f);
+      },
+      error_code, "Cannot open file 'nonexistent'");
+
+  EXPECT_EQ("First, thou shalt count to three",
+            fmt::format("First, thou shalt count to {0}", "three"));
+  EXPECT_EQ(fmt::format("Bring me a {}", "shrubbery"), "Bring me a shrubbery");
+  EXPECT_EQ(fmt::format("From {} to {}", 1, 3), "From 1 to 3");
+
+  char buffer[buffer_size];
+  safe_sprintf(buffer, "%03.2f", -1.2);
+  EXPECT_EQ(buffer, fmt::format("{:03.2f}", -1.2));
+
+  EXPECT_EQ(fmt::format("{0}, {1}, {2}", 'a', 'b', 'c'), "a, b, c");
+  EXPECT_EQ(fmt::format("{}, {}, {}", 'a', 'b', 'c'), "a, b, c");
+  EXPECT_EQ(fmt::format("{2}, {1}, {0}", 'a', 'b', 'c'), "c, b, a");
+  EXPECT_EQ(fmt::format("{0}{1}{0}", "abra", "cad"), "abracadabra");
+
+  EXPECT_EQ("left aligned                  ",
+            fmt::format("{:<30}", "left aligned"));
+  EXPECT_EQ("                 right aligned",
+            fmt::format("{:>30}", "right aligned"));
+  EXPECT_EQ("           centered           ",
+            fmt::format("{:^30}", "centered"));
+  EXPECT_EQ("***********centered***********",
+            fmt::format("{:*^30}", "centered"));
+
+  EXPECT_EQ(fmt::format("{:+f}; {:+f}", 3.14, -3.14), "+3.140000; -3.140000");
+  EXPECT_EQ(fmt::format("{: f}; {: f}", 3.14, -3.14), " 3.140000; -3.140000");
+  EXPECT_EQ(fmt::format("{:-f}; {:-f}", 3.14, -3.14), "3.140000; -3.140000");
+
+  EXPECT_EQ("int: 42;  hex: 2a;  oct: 52",
+            fmt::format("int: {0:d};  hex: {0:x};  oct: {0:o}", 42));
+  EXPECT_EQ("int: 42;  hex: 0x2a;  oct: 052",
+            fmt::format("int: {0:d};  hex: {0:#x};  oct: {0:#o}", 42));
+
+  EXPECT_EQ(fmt::format("The answer is {}", 42), "The answer is 42");
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("The answer is {:d}"), "forty-two"),
+      format_error, "invalid format specifier");
+
+  EXPECT_WRITE(
+      stdout, fmt::print("{}", std::numeric_limits<double>::infinity()), "inf");
+}
+
+TEST(format_test, print) {
+  EXPECT_WRITE(stdout, fmt::print("Don't {}!", "panic"), "Don't panic!");
+  EXPECT_WRITE(stderr, fmt::print(stderr, "Don't {}!", "panic"),
+               "Don't panic!");
+  EXPECT_WRITE(stdout, fmt::println("Don't {}!", "panic"), "Don't panic!\n");
+  EXPECT_WRITE(stderr, fmt::println(stderr, "Don't {}!", "panic"),
+               "Don't panic!\n");
+}
+
+TEST(format_test, variadic) {
+  EXPECT_EQ(fmt::format("{}c{}", "ab", 1), "abc1");
+}
+
+TEST(format_test, bytes) {
+  auto s = fmt::format("{:10}", fmt::bytes("ёжик"));
+  EXPECT_EQ("ёжик  ", s);
+  EXPECT_EQ(10, s.size());
+}
+
+TEST(format_test, group_digits_view) {
+  EXPECT_EQ(fmt::format("{}", fmt::group_digits(10000000)), "10,000,000");
+  EXPECT_EQ(fmt::format("{:8}", fmt::group_digits(1000)), "   1,000");
+}
+
+#ifdef __cpp_generic_lambdas
+struct point {
+  double x, y;
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<point> : nested_formatter<double> {
+  auto format(point p, format_context& ctx) const -> decltype(ctx.out()) {
+    return write_padded(ctx, [this, p](auto out) -> decltype(out) {
+      return fmt::format_to(out, "({}, {})", nested(p.x), nested(p.y));
+    });
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(format_test, nested_formatter) {
+  EXPECT_EQ(fmt::format("{:>16.2f}", point{1, 2}), "    (1.00, 2.00)");
+}
+#endif  // __cpp_generic_lambdas
+
+enum test_enum { foo, bar };
+auto format_as(test_enum e) -> int { return e; }
+
+TEST(format_test, join) {
+  using fmt::join;
+  int v1[3] = {1, 2, 3};
+  auto v2 = std::vector<float>();
+  v2.push_back(1.2f);
+  v2.push_back(3.4f);
+  void* v3[2] = {&v1[0], &v1[1]};
+
+  EXPECT_EQ(fmt::format("({})", join(v1, v1 + 3, ", ")), "(1, 2, 3)");
+  EXPECT_EQ(fmt::format("({})", join(v1, v1 + 1, ", ")), "(1)");
+  EXPECT_EQ(fmt::format("({})", join(v1, v1, ", ")), "()");
+  EXPECT_EQ(fmt::format("({:03})", join(v1, v1 + 3, ", ")), "(001, 002, 003)");
+  EXPECT_EQ("(+01.20, +03.40)",
+            fmt::format("({:+06.2f})", join(v2.begin(), v2.end(), ", ")));
+
+  EXPECT_EQ(fmt::format("{0:{1}}", join(v1, v1 + 3, ", "), 1), "1, 2, 3");
+
+  EXPECT_EQ(fmt::format("{}, {}", v3[0], v3[1]),
+            fmt::format("{}", join(v3, v3 + 2, ", ")));
+
+  EXPECT_EQ(fmt::format("({})", join(v1, ", ")), "(1, 2, 3)");
+  EXPECT_EQ(fmt::format("({:+06.2f})", join(v2, ", ")), "(+01.20, +03.40)");
+
+  auto v4 = std::vector<test_enum>{foo, bar, foo};
+  EXPECT_EQ(fmt::format("{}", join(v4, " ")), "0 1 0");
+}
+
+#ifdef __cpp_lib_byte
+TEST(format_test, join_bytes) {
+  auto v = std::vector<std::byte>{std::byte(1), std::byte(2), std::byte(3)};
+  EXPECT_EQ(fmt::format("{}", fmt::join(v, ", ")), "1, 2, 3");
+}
+#endif
+
+std::string vformat_message(int id, const char* format, fmt::format_args args) {
+  auto buffer = fmt::memory_buffer();
+  fmt::format_to(fmt::appender(buffer), "[{}] ", id);
+  vformat_to(fmt::appender(buffer), format, args);
+  return to_string(buffer);
+}
+
+template <typename... Args>
+std::string format_message(int id, const char* format, const Args&... args) {
+  auto va = fmt::make_format_args(args...);
+  return vformat_message(id, format, va);
+}
+
+TEST(format_test, format_message_example) {
+  EXPECT_EQ("[42] something happened",
+            format_message(42, "{} happened", "something"));
+}
+
+template <typename... Args>
+void print_error(const char* file, int line, const char* format,
+                 const Args&... args) {
+  fmt::print("{}: {}: ", file, line);
+  fmt::print(format, args...);
+}
+
+TEST(format_test, unpacked_args) {
+  EXPECT_EQ("0123456789abcdefg",
+            fmt::format("{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}", 0, 1, 2, 3, 4, 5,
+                        6, 7, 8, 9, 'a', 'b', 'c', 'd', 'e', 'f', 'g'));
+}
+
+constexpr char with_null[3] = {'{', '}', '\0'};
+constexpr char no_null[2] = {'{', '}'};
+static constexpr const char static_with_null[3] = {'{', '}', '\0'};
+static constexpr const char static_no_null[2] = {'{', '}'};
+
+TEST(format_test, compile_time_string) {
+  EXPECT_EQ(fmt::format(FMT_STRING("foo")), "foo");
+  EXPECT_EQ(fmt::format(FMT_STRING("{}"), 42), "42");
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+  using namespace fmt::literals;
+  EXPECT_EQ("foobar", fmt::format(FMT_STRING("{foo}{bar}"), "bar"_a = "bar",
+                                  "foo"_a = "foo"));
+  EXPECT_EQ(fmt::format(FMT_STRING("")), "");
+  EXPECT_EQ(fmt::format(FMT_STRING(""), "arg"_a = 42), "");
+  EXPECT_EQ(fmt::format(FMT_STRING("{answer}"), "answer"_a = Answer()), "42");
+  EXPECT_EQ(fmt::format(FMT_STRING("{} {two}"), 1, "two"_a = 2), "1 2");
+#endif
+
+  (void)static_with_null;
+  (void)static_no_null;
+#ifndef _MSC_VER
+  EXPECT_EQ(fmt::format(FMT_STRING(static_with_null), 42), "42");
+  EXPECT_EQ(fmt::format(FMT_STRING(static_no_null), 42), "42");
+#endif
+
+  (void)with_null;
+  (void)no_null;
+#if FMT_CPLUSPLUS >= 201703L
+  EXPECT_EQ(fmt::format(FMT_STRING(with_null), 42), "42");
+  EXPECT_EQ(fmt::format(FMT_STRING(no_null), 42), "42");
+#endif
+#if defined(FMT_USE_STRING_VIEW) && FMT_CPLUSPLUS >= 201703L
+  EXPECT_EQ(fmt::format(FMT_STRING(std::string_view("{}")), 42), "42");
+#endif
+}
+
+TEST(format_test, custom_format_compile_time_string) {
+  EXPECT_EQ(fmt::format(FMT_STRING("{}"), Answer()), "42");
+  auto answer = Answer();
+  EXPECT_EQ(fmt::format(FMT_STRING("{}"), answer), "42");
+  char buf[10] = {};
+  fmt::format_to(buf, FMT_STRING("{}"), answer);
+  const Answer const_answer = Answer();
+  EXPECT_EQ(fmt::format(FMT_STRING("{}"), const_answer), "42");
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS
+TEST(format_test, named_arg_udl) {
+  using namespace fmt::literals;
+  auto udl_a = fmt::format("{first}{second}{first}{third}", "first"_a = "abra",
+                           "second"_a = "cad", "third"_a = 99);
+  EXPECT_EQ(
+      fmt::format("{first}{second}{first}{third}", fmt::arg("first", "abra"),
+                  fmt::arg("second", "cad"), fmt::arg("third", 99)),
+      udl_a);
+
+  EXPECT_EQ(fmt::format("{answer}", "answer"_a = Answer()), "42");
+}
+#endif  // FMT_USE_USER_DEFINED_LITERALS
+
+TEST(format_test, enum) { EXPECT_EQ(fmt::format("{}", foo), "0"); }
+
+TEST(format_test, formatter_not_specialized) {
+  static_assert(!fmt::has_formatter<fmt::formatter<test_enum>,
+                                    fmt::format_context>::value,
+                "");
+}
+
+#if FMT_HAS_FEATURE(cxx_strong_enums)
+enum big_enum : unsigned long long { big_enum_value = 5000000000ULL };
+auto format_as(big_enum e) -> unsigned long long { return e; }
+
+TEST(format_test, strong_enum) {
+  EXPECT_EQ(fmt::format("{}", big_enum_value), "5000000000");
+}
+#endif
+
+TEST(format_test, non_null_terminated_format_string) {
+  EXPECT_EQ(fmt::format(string_view("{}foo", 2), 42), "42");
+}
+
+namespace adl_test {
+namespace fmt {
+namespace detail {
+struct foo {};
+template <typename, typename OutputIt> void write(OutputIt, foo) = delete;
+}  // namespace detail
+}  // namespace fmt
+}  // namespace adl_test
+
+FMT_BEGIN_NAMESPACE
+template <>
+struct formatter<adl_test::fmt::detail::foo> : formatter<std::string> {
+  auto format(adl_test::fmt::detail::foo, format_context& ctx)
+      -> decltype(ctx.out()) {
+    return formatter<std::string>::format("foo", ctx);
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(format_test, to_string) {
+  EXPECT_EQ(fmt::to_string(42), "42");
+  EXPECT_EQ(fmt::to_string(reinterpret_cast<void*>(0x1234)), "0x1234");
+  EXPECT_EQ(fmt::to_string(adl_test::fmt::detail::foo()), "foo");
+  EXPECT_EQ(fmt::to_string(foo), "0");
+
+#if FMT_USE_FLOAT128
+  EXPECT_EQ(fmt::to_string(__float128(0.5)), "0.5");
+#endif
+
+#if defined(FMT_USE_STRING_VIEW) && FMT_CPLUSPLUS >= 201703L
+  EXPECT_EQ(fmt::to_string(std::string_view()), "");
+#endif
+}
+
+TEST(format_test, output_iterators) {
+  std::list<char> out;
+  fmt::format_to(std::back_inserter(out), "{}", 42);
+  EXPECT_EQ("42", std::string(out.begin(), out.end()));
+  std::stringstream s;
+  fmt::format_to(std::ostream_iterator<char>(s), "{}", 42);
+  EXPECT_EQ("42", s.str());
+}
+
+TEST(format_test, formatted_size) {
+  EXPECT_EQ(2u, fmt::formatted_size("{}", 42));
+  EXPECT_EQ(2u, fmt::formatted_size(std::locale(), "{}", 42));
+}
+
+TEST(format_test, format_to_no_args) {
+  std::string s;
+  fmt::format_to(std::back_inserter(s), "test");
+  EXPECT_EQ("test", s);
+}
+
+TEST(format_test, format_to) {
+  std::string s;
+  fmt::format_to(std::back_inserter(s), "part{0}", 1);
+  EXPECT_EQ("part1", s);
+  fmt::format_to(std::back_inserter(s), "part{0}", 2);
+  EXPECT_EQ("part1part2", s);
+}
+
+TEST(format_test, format_to_memory_buffer) {
+  auto buf = fmt::basic_memory_buffer<char, 100>();
+  fmt::format_to(fmt::appender(buf), "{}", "foo");
+  EXPECT_EQ("foo", to_string(buf));
+}
+
+TEST(format_test, format_to_vector) {
+  std::vector<char> v;
+  fmt::format_to(std::back_inserter(v), "{}", "foo");
+  EXPECT_EQ(string_view(v.data(), v.size()), "foo");
+}
+
+struct nongrowing_container {
+  using value_type = char;
+  void push_back(char) { throw std::runtime_error("can't take it any more"); }
+};
+
+TEST(format_test, format_to_propagates_exceptions) {
+  auto c = nongrowing_container();
+  EXPECT_THROW(fmt::format_to(std::back_inserter(c), "{}", 42),
+               std::runtime_error);
+}
+
+TEST(format_test, format_to_n) {
+  char buffer[4];
+  buffer[3] = 'x';
+  auto result = fmt::format_to_n(buffer, 3, "{}", 12345);
+  EXPECT_EQ(5u, result.size);
+  EXPECT_EQ(buffer + 3, result.out);
+  EXPECT_EQ("123x", fmt::string_view(buffer, 4));
+
+  result = fmt::format_to_n(buffer, 3, "{:s}", "foobar");
+  EXPECT_EQ(6u, result.size);
+  EXPECT_EQ(buffer + 3, result.out);
+  EXPECT_EQ("foox", fmt::string_view(buffer, 4));
+
+  buffer[0] = 'x';
+  buffer[1] = 'x';
+  buffer[2] = 'x';
+  result = fmt::format_to_n(buffer, 3, "{}", 'A');
+  EXPECT_EQ(1u, result.size);
+  EXPECT_EQ(buffer + 1, result.out);
+  EXPECT_EQ("Axxx", fmt::string_view(buffer, 4));
+
+  result = fmt::format_to_n(buffer, 3, "{}{} ", 'B', 'C');
+  EXPECT_EQ(3u, result.size);
+  EXPECT_EQ(buffer + 3, result.out);
+  EXPECT_EQ("BC x", fmt::string_view(buffer, 4));
+
+  result = fmt::format_to_n(buffer, 4, "{}", "ABCDE");
+  EXPECT_EQ(5u, result.size);
+  EXPECT_EQ("ABCD", fmt::string_view(buffer, 4));
+
+  buffer[3] = 'x';
+  result = fmt::format_to_n(buffer, 3, "{}", std::string(1000, '*'));
+  EXPECT_EQ(1000u, result.size);
+  EXPECT_EQ("***x", fmt::string_view(buffer, 4));
+}
+
+struct test_output_iterator {
+  char* data;
+
+  using iterator_category = std::output_iterator_tag;
+  using value_type = void;
+  using difference_type = void;
+  using pointer = void;
+  using reference = void;
+
+  auto operator++() -> test_output_iterator& {
+    ++data;
+    return *this;
+  }
+  auto operator++(int) -> test_output_iterator {
+    auto tmp = *this;
+    ++data;
+    return tmp;
+  }
+  auto operator*() -> char& { return *data; }
+};
+
+TEST(format_test, format_to_n_output_iterator) {
+  char buf[10] = {};
+  fmt::format_to_n(test_output_iterator{buf}, 10, "{}", 42);
+  EXPECT_STREQ(buf, "42");
+}
+
+TEST(format_test, vformat_to) {
+  using context = fmt::format_context;
+  int n = 42;
+  auto args = fmt::make_format_args<context>(n);
+  auto s = std::string();
+  fmt::vformat_to(std::back_inserter(s), "{}", args);
+  EXPECT_EQ(s, "42");
+  s.clear();
+  fmt::vformat_to(std::back_inserter(s), FMT_STRING("{}"), args);
+  EXPECT_EQ(s, "42");
+}
+
+TEST(format_test, char_traits_not_ambiguous) {
+  // Test that we don't inject detail names into the std namespace.
+  using namespace std;
+  auto c = char_traits<char>::char_type();
+  (void)c;
+#if FMT_CPLUSPLUS >= 201103L
+  auto s = std::string();
+  auto lval = begin(s);
+  (void)lval;
+#endif
+}
+
+struct check_back_appender {};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<check_back_appender> {
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename Context>
+  auto format(check_back_appender, Context& ctx) -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    static_assert(std::is_same<decltype(++out), decltype(out)&>::value,
+                  "needs to satisfy weakly_incrementable");
+    *out = 'y';
+    return ++out;
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(format_test, back_insert_slicing) {
+  EXPECT_EQ(fmt::format("{}", check_back_appender{}), "y");
+}
+
+namespace test {
+enum class scoped_enum_as_int {};
+auto format_as(scoped_enum_as_int) -> int { return 42; }
+
+enum class scoped_enum_as_string_view {};
+auto format_as(scoped_enum_as_string_view) -> fmt::string_view { return "foo"; }
+
+enum class scoped_enum_as_string {};
+auto format_as(scoped_enum_as_string) -> std::string { return "foo"; }
+
+struct struct_as_int {};
+auto format_as(struct_as_int) -> int { return 42; }
+
+struct struct_as_const_reference {
+  const std::string name = "foo";
+};
+auto format_as(const struct_as_const_reference& s) -> const std::string& {
+  return s.name;
+}
+}  // namespace test
+
+TEST(format_test, format_as) {
+  EXPECT_EQ(fmt::format("{}", test::scoped_enum_as_int()), "42");
+  EXPECT_EQ(fmt::format("{}", test::scoped_enum_as_string_view()), "foo");
+  EXPECT_EQ(fmt::format("{}", test::scoped_enum_as_string()), "foo");
+  EXPECT_EQ(fmt::format("{}", test::struct_as_int()), "42");
+  EXPECT_EQ(fmt::format("{}", test::struct_as_const_reference()), "foo");
+}
+
+TEST(format_test, format_as_to_string) {
+  EXPECT_EQ(fmt::to_string(test::scoped_enum_as_int()), "42");
+  EXPECT_EQ(fmt::to_string(test::scoped_enum_as_string_view()), "foo");
+  EXPECT_EQ(fmt::to_string(test::scoped_enum_as_string()), "foo");
+  EXPECT_EQ(fmt::to_string(test::struct_as_int()), "42");
+}
+
+template <typename Char, typename T> auto check_enabled_formatter() -> bool {
+  static_assert(std::is_default_constructible<fmt::formatter<T, Char>>::value,
+                "");
+  return true;
+}
+
+template <typename Char, typename... T> void check_enabled_formatters() {
+  auto dummy = {check_enabled_formatter<Char, T>()...};
+  (void)dummy;
+}
+
+TEST(format_test, test_formatters_enabled) {
+  check_enabled_formatters<char, bool, char, signed char, unsigned char, short,
+                           unsigned short, int, unsigned, long, unsigned long,
+                           long long, unsigned long long, float, double,
+                           long double, void*, const void*, char*, const char*,
+                           std::string, std::nullptr_t>();
+  check_enabled_formatters<wchar_t, bool, wchar_t, signed char, unsigned char,
+                           short, unsigned short, int, unsigned, long,
+                           unsigned long, long long, unsigned long long, float,
+                           double, long double, void*, const void*, wchar_t*,
+                           const wchar_t*, std::wstring, std::nullptr_t>();
+}
+
+TEST(format_int_test, data) {
+  fmt::format_int format_int(42);
+  EXPECT_EQ(std::string(format_int.data(), format_int.size()), "42");
+}
+
+TEST(format_int_test, format_int) {
+  EXPECT_EQ(fmt::format_int(42).str(), "42");
+  EXPECT_EQ(fmt::format_int(42).size(), 2u);
+  EXPECT_EQ(fmt::format_int(-42).str(), "-42");
+  EXPECT_EQ(fmt::format_int(-42).size(), 3u);
+  EXPECT_EQ(fmt::format_int(42ul).str(), "42");
+  EXPECT_EQ(fmt::format_int(-42l).str(), "-42");
+  EXPECT_EQ(fmt::format_int(42ull).str(), "42");
+  EXPECT_EQ(fmt::format_int(-42ll).str(), "-42");\
+  EXPECT_EQ(fmt::format_int(max_value<int64_t>()).str(),
+            std::to_string(max_value<int64_t>()));
+}
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+
+#  include <locale>
+
+class format_facet : public fmt::format_facet<std::locale> {
+ protected:
+  struct int_formatter {
+    fmt::appender out;
+
+    template <typename T, FMT_ENABLE_IF(fmt::detail::is_integer<T>::value)>
+    auto operator()(T value) -> bool {
+      fmt::format_to(out, "[{}]", value);
+      return true;
+    }
+
+    template <typename T, FMT_ENABLE_IF(!fmt::detail::is_integer<T>::value)>
+    auto operator()(T) -> bool {
+      return false;
+    }
+  };
+
+  auto do_put(fmt::appender out, fmt::loc_value val,
+              const fmt::format_specs<>&) const -> bool override;
+};
+
+auto format_facet::do_put(fmt::appender out, fmt::loc_value val,
+                          const fmt::format_specs<>&) const -> bool {
+  return val.visit(int_formatter{out});
+}
+
+TEST(format_test, format_facet) {
+  auto loc = std::locale(std::locale(), new format_facet());
+  EXPECT_EQ(fmt::format(loc, "{:L}", 42), "[42]");
+  EXPECT_EQ(fmt::format(loc, "{:L}", -42), "[-42]");
+}
+
+TEST(format_test, format_facet_separator) {
+  // U+2019 RIGHT SINGLE QUOTATION MARK is a digit separator in the de_CH
+  // locale.
+  auto loc =
+      std::locale({}, new fmt::format_facet<std::locale>("\xe2\x80\x99"));
+  EXPECT_EQ(fmt::format(loc, "{:L}", 1000),
+            "1\xe2\x80\x99"
+            "000");
+}
+
+TEST(format_test, format_facet_grouping) {
+  auto loc =
+      std::locale({}, new fmt::format_facet<std::locale>(",", {1, 2, 3}));
+  EXPECT_EQ(fmt::format(loc, "{:L}", 1234567890), "1,234,567,89,0");
+}
+
+TEST(format_test, format_named_arg_with_locale) {
+  EXPECT_EQ(fmt::format(std::locale(), "{answer}", fmt::arg("answer", 42)),
+            "42");
+}
+
+TEST(format_test, format_locale) {
+  auto loc = std::locale({}, new fmt::format_facet<std::locale>(","));
+  EXPECT_EQ(fmt::format(loc, "{:Lx}", 123456789), "7,5bc,d15");
+  EXPECT_EQ(fmt::format(loc, "{:#Lb}", -123456789),
+            "-0b111,010,110,111,100,110,100,010,101");
+  EXPECT_EQ(fmt::format(loc, "{:10Lo}", 12345), "    30,071");
+}
+
+#endif  // FMT_STATIC_THOUSANDS_SEPARATOR
+
+struct convertible_to_nonconst_cstring {
+  operator char*() const {
+    static char c[] = "bar";
+    return c;
+  }
+};
+
+FMT_BEGIN_NAMESPACE
+template <>
+struct formatter<convertible_to_nonconst_cstring> : formatter<char*> {};
+FMT_END_NAMESPACE
+
+TEST(format_test, formatter_nonconst_char) {
+  EXPECT_EQ(fmt::format("{}", convertible_to_nonconst_cstring()), "bar");
+}