libcxx/test/std/containers/container.adaptors/container.adaptors.format/format.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 // UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
  12
  13 // [container.adaptors.format]
  14 // For each of queue, priority_queue, and stack, the library provides the
  15 // following formatter specialization where adaptor-type is the name of the
  16 // template:
  17 //
  18 // template<class charT, class T, formattable<charT> Container, class... U>
  19 //   struct formatter<adaptor-type<T, Container, U...>, charT>
  20
  21 // template<class FormatContext>
  22 //   typename FormatContext::iterator
  23 //     format(maybe-const-adaptor& r, FormatContext& ctx) const;
  24
  25 // Note this tests the basics of this function. It's tested in more detail in
  26 // the format functions test.
  27
  28 #include <array>
  29 #include <cassert>
  30 #include <concepts>
  31 #include <format>
  32 #include <queue>
  33 #include <stack>
  34
  35 #include "test_format_context.h"
  36 #include "test_macros.h"
  37 #include "make_string.h"
  38
  39 #define SV(S) MAKE_STRING_VIEW(CharT, S)
  40
  41 template <class StringViewT, class Arg>
  42 void test_format(StringViewT expected, Arg arg) {
  43   using CharT      = typename StringViewT::value_type;
  44   using String     = std::basic_string<CharT>;
  45   using OutIt      = std::back_insert_iterator<String>;
  46   using FormatCtxT = std::basic_format_context<OutIt, CharT>;
  47
  48   const std::formatter<Arg, CharT> formatter;
  49
  50   String result;
  51   OutIt out             = std::back_inserter(result);
  52   FormatCtxT format_ctx = test_format_context_create<OutIt, CharT>(out, std::make_format_args<FormatCtxT>(arg));
  53   formatter.format(arg, format_ctx);
  54   assert(result == expected);
  55 }
  56
  57 template <class CharT>
  58 void test_fmt() {
  59   std::array input{1, 42, 99, 0};
  60   test_format(SV("[1, 42, 99, 0]"), std::queue<int>{input.begin(), input.end()});
  61   test_format(SV("[99, 42, 1, 0]"), std::priority_queue<int>{input.begin(), input.end()});
  62   test_format(SV("[1, 42, 99, 0]"), std::stack<int>{input.begin(), input.end()});
  63 }
  64
  65 void test() {
  66   test_fmt<char>();
  67 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  68   test_fmt<wchar_t>();
  69 #endif
  70 }
  71
  72 int main(int, char**) {
  73   test();
  74
  75   return 0;
  76 }