xref: /llvm-project/libcxx/test/std/utilities/format/format.functions/P2418.pass.cpp (revision f0fc8c4878ed3ed60bd7536f97ef2673eb691ae7)
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: libcpp-has-no-incomplete-format
10 // TODO FMT Evaluate gcc-12 status
11 // UNSUPPORTED: gcc-12
12 
13 // TODO FMT This test should not require std::to_chars(floating-point)
14 // XFAIL: availability-fp_to_chars-missing
15 
16 // Tests whether a move only type can be formatted. This is required by
17 // P2418R2 "Add support for std::generator-like types to std::format"
18 
19 // <format>
20 
21 #include <format>
22 #include <cassert>
23 
24 #include "MoveOnly.h"
25 #include "make_string.h"
26 #include "test_macros.h"
27 
28 #ifndef TEST_HAS_NO_LOCALIZATION
29 #  include <locale>
30 #endif
31 
32 #define SV(S) MAKE_STRING_VIEW(CharT, S)
33 
34 template <class CharT>
35 struct std::formatter<MoveOnly, CharT> : std::formatter<int, CharT> {
36   auto format(const MoveOnly& m, auto& ctx) const -> decltype(ctx.out()) {
37     return std::formatter<int, CharT>::format(m.get(), ctx);
38   }
39 };
40 
41 template <class CharT>
42 static void test() {
43   MoveOnly m{10};
44   CharT buffer[10];
45 #ifndef TEST_HAS_NO_LOCALIZATION
46   std::locale loc;
47 #endif
48 
49   assert(std::format(SV("{}"), MoveOnly{}) == SV("1"));
50 
51   assert(std::format(SV("{}"), m) == SV("10"));
52   assert(m.get() == 10);
53 
54   assert(std::format(SV("{}"), std::move(m)) == SV("10"));
55   assert(m.get() == 10);
56 
57 #ifndef TEST_HAS_NO_LOCALIZATION
58   assert(std::format(loc, SV("{}"), MoveOnly{}) == SV("1"));
59 
60   assert(std::format(loc, SV("{}"), m) == SV("10"));
61   assert(m.get() == 10);
62 
63   assert(std::format(loc, SV("{}"), std::move(m)) == SV("10"));
64   assert(m.get() == 10);
65 #endif
66 
67   assert(std::format_to(buffer, SV("{}"), MoveOnly{}) == &buffer[1]);
68 
69   assert(std::format_to(buffer, SV("{}"), m) == &buffer[2]);
70   assert(m.get() == 10);
71 
72   assert(std::format_to(buffer, SV("{}"), std::move(m)) == &buffer[2]);
73   assert(m.get() == 10);
74 
75 #ifndef TEST_HAS_NO_LOCALIZATION
76   assert(std::format_to(buffer, loc, SV("{}"), MoveOnly{}) == &buffer[1]);
77 
78   assert(std::format_to(buffer, loc, SV("{}"), m) == &buffer[2]);
79   assert(m.get() == 10);
80 
81   assert(std::format_to(buffer, loc, SV("{}"), std::move(m)) == &buffer[2]);
82   assert(m.get() == 10);
83 #endif
84 
85   assert(std::format_to_n(buffer, 5, SV("{}"), MoveOnly{}).out == &buffer[1]);
86 
87   assert(std::format_to_n(buffer, 5, SV("{}"), m).out == &buffer[2]);
88   assert(m.get() == 10);
89 
90   assert(std::format_to_n(buffer, 5, SV("{}"), std::move(m)).out == &buffer[2]);
91   assert(m.get() == 10);
92 
93 #ifndef TEST_HAS_NO_LOCALIZATION
94   assert(std::format_to_n(buffer, 5, loc, SV("{}"), MoveOnly{}).out == &buffer[1]);
95 
96   assert(std::format_to_n(buffer, 5, loc, SV("{}"), m).out == &buffer[2]);
97   assert(m.get() == 10);
98 
99   assert(std::format_to_n(buffer, 5, loc, SV("{}"), std::move(m)).out == &buffer[2]);
100   assert(m.get() == 10);
101 #endif
102 
103   assert(std::formatted_size(SV("{}"), MoveOnly{}) == 1);
104 
105   assert(std::formatted_size(SV("{}"), m) == 2);
106   assert(m.get() == 10);
107 
108   assert(std::formatted_size(SV("{}"), std::move(m)) == 2);
109   assert(m.get() == 10);
110 
111 #ifndef TEST_HAS_NO_LOCALIZATION
112   assert(std::formatted_size(loc, SV("{}"), MoveOnly{}) == 1);
113 
114   assert(std::formatted_size(loc, SV("{}"), m) == 2);
115   assert(m.get() == 10);
116 
117   assert(std::formatted_size(loc, SV("{}"), std::move(m)) == 2);
118   assert(m.get() == 10);
119 #endif
120 }
121 
122 int main(int, char**) {
123   test<char>();
124 
125 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
126   test<wchar_t>();
127 #endif
128 
129   return 0;
130 }
131