libcxx/test/std/utilities/format/format.functions/vformat_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>
  17 //   Out vformat_to(Out out, const locale& loc, string_view fmt,
  18 //                  format_args args);
  19 // template<class Out>
  20 //    Out vformat_to(Out out, const locale& loc, wstring_view fmt,
  21 //                   wformat_args args);
  22
  23 #include <format>
  24 #include <algorithm>
  25 #include <cassert>
  26 #include <list>
  27 #include <vector>
  28
  29 #include "assert_macros.h"
  30 #include "concat_macros.h"
  31 #include "format_tests.h"
  32 #include "string_literal.h"
  33
  34 auto test = []<class CharT, class... Args>(
  35                 std::basic_string_view<CharT> expected, std::basic_string_view<CharT> fmt, Args&&... args) constexpr {
  36   {
  37     std::basic_string<CharT> out(expected.size(), CharT(' '));
  38     auto it = std::vformat_to(out.begin(), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
  39     assert(it == out.end());
  40     assert(out == expected);
  41   }
  42   {
  43     std::list<CharT> out;
  44     std::vformat_to(std::back_inserter(out), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
  45     assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
  46   }
  47   {
  48     std::vector<CharT> out;
  49     std::vformat_to(std::back_inserter(out), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
  50     assert(std::equal(out.begin(), out.end(), expected.begin(), expected.end()));
  51   }
  52   {
  53     assert(expected.size() < 4096 && "Update the size of the buffer.");
  54     CharT out[4096];
  55     CharT* it = std::vformat_to(out, std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
  56     assert(std::distance(out, it) == int(expected.size()));
  57     // Convert to std::string since output contains '\0' for boolean tests.
  58     assert(std::basic_string<CharT>(out, it) == expected);
  59   }
  60 };
  61
  62 auto test_exception = []<class CharT, class... Args>([[maybe_unused]] std::string_view what,
  63                                                      [[maybe_unused]] std::basic_string_view<CharT> fmt,
  64                                                      [[maybe_unused]] Args&&... args) {
  65   TEST_VALIDATE_EXCEPTION(
  66       std::format_error,
  67       [&]([[maybe_unused]] const std::format_error& e) {
  68         TEST_LIBCPP_REQUIRE(
  69             e.what() == what,
  70             TEST_WRITE_CONCATENATED(
  71                 "\nFormat string   ", fmt, "\nExpected exception ", what, "\nActual exception   ", e.what(), '\n'));
  72       },
  73       [&] {
  74         std::basic_string<CharT> out;
  75         std::vformat_to(std::back_inserter(out), std::locale(), fmt, std::make_format_args<context_t<CharT>>(args...));
  76       }());
  77 };
  78
  79 int main(int, char**) {
  80   format_tests<char, execution_modus::partial>(test, test_exception);
  81
  82 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  83   format_tests_char_to_wchar_t(test);
  84   format_tests<wchar_t, execution_modus::partial>(test, test_exception);
  85 #endif
  86
  87   return 0;
  88 }