libcxx/test/std/utilities/format/format.functions/format_to.locale.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   3 // See https://llvm.org/LICENSE.txt for license information.
   4 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   5 //
   6 //===----------------------------------------------------------------------===//
   7
   8 // UNSUPPORTED: c++03, c++11, c++14, c++17
   9 // UNSUPPORTED: no-localization
  10 // UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
  11
  12 // XFAIL: availability-fp_to_chars-missing
  13
  14 // <format>
  15
  16 // template<class Out, class... Args>
  17 //   Out format_to(Out out, const locale& loc,
  18 //                 format-string<Args...> fmt, const Args&... args);
  19 // template<class Out, class... Args>
  20 //   Out format_to(Out out, const locale& loc,
  21 //                 wformat-string<Args...> fmt, const Args&... args);
  22
  23 #include <format>
  24 #include <algorithm>
  25 #include <cassert>
  26 #include <iterator>
  27 #include <list>
  28 #include <vector>
  29
  30 #include "test_macros.h"
  31 #include "format_tests.h"
  32 #include "string_literal.h"
  33 #include "test_format_string.h"
  34 #include "test_iterators.h"
  35
  36 auto test =
  37     []<class CharT, class... Args>(
  38         std::basic_string_view<CharT> expected, test_format_string<CharT, Args...> fmt, Args&&... args) constexpr {
  39       {
  40         std::basic_string<CharT> out(expected.size(), CharT(' '));
  41         auto it = std::format_to(out.begin(), std::locale(), fmt, std::forward<Args>(args)...);
  42         assert(it == out.end());
  43         assert(out == expected);
  44       }
  45       {
  46         std::list<CharT> out;
  47         std::format_to(std::back_inserter(out), std::locale(), fmt, std::forward<Args>(args)...);
  48         assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
  49       }
  50       {
  51         std::vector<CharT> out;
  52         std::format_to(std::back_inserter(out), std::locale(), fmt, std::forward<Args>(args)...);
  53         assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
  54       }
  55       {
  56         assert(expected.size() < 4096 && "Update the size of the buffer.");
  57         CharT out[4096];
  58         cpp20_output_iterator<CharT*> it =
  59             std::format_to(cpp20_output_iterator{out}, std::locale(), fmt, std::forward<Args>(args)...);
  60         assert(std::distance(out, base(it)) == int(expected.size()));
  61         // Convert to std::string since output contains '\0' for boolean tests.
  62         assert(std::basic_string<CharT>(out, base(it)) == expected);
  63       }
  64     };
  65
  66 auto test_exception = []<class CharT, class... Args>(std::string_view, std::basic_string_view<CharT>, Args&&...) {
  67   // After P2216 most exceptions thrown by std::format_to become ill-formed.
  68   // Therefore this tests does nothing.
  69   // A basic ill-formed test is done in format_to.locale.verify.cpp
  70   // The exceptions are tested by other functions that don't use the basic-format-string as fmt argument.
  71 };
  72
  73 int main(int, char**) {
  74   format_tests<char, execution_modus::partial>(test, test_exception);
  75
  76 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  77   format_tests_char_to_wchar_t(test);
  78   format_tests<wchar_t, execution_modus::partial>(test, test_exception);
  79 #endif
  80
  81   return 0;
  82 }