libcxx/test/std/utilities/format/format.formattable/concept.formattable.float.compile.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
  10
  11 // <format>
  12
  13 // template<class T, class charT>
  14 // concept formattable = ...
  15
  16 #include <concepts>
  17 #include <format>
  18
  19 #include "test_macros.h"
  20
  21 template <class T, class CharT>
  22 void assert_is_not_formattable() {
  23   static_assert(!std::formattable<T, CharT>);
  24 }
  25
  26 template <class T, class CharT>
  27 void assert_is_formattable() {
  28   // Only formatters for CharT == char || CharT == wchar_t are enabled for the
  29   // standard formatters. When CharT is a different type the formatter should
  30   // be disabled.
  31   if constexpr (std::same_as<CharT, char>
  32 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  33                 || std::same_as<CharT, wchar_t>
  34 #endif
  35   )
  36     static_assert(std::formattable<T, CharT>);
  37   else
  38     assert_is_not_formattable<T, CharT>();
  39 }
  40
  41 template <class CharT>
  42 void test() {
  43   assert_is_formattable<float, CharT>();
  44   assert_is_formattable<double, CharT>();
  45   assert_is_formattable<long double, CharT>();
  46 }
  47
  48 void test() {
  49   test<char>();
  50 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  51   test<wchar_t>();
  52 #endif
  53   test<char8_t>();
  54   test<char16_t>();
  55   test<char32_t>();
  56
  57   test<int>();
  58 }