xref: /llvm-project/libcxx/test/std/utilities/format/format.functions/P2418.pass.cpp (revision 520c7fbbd0356f135a19cc764ff70e7f52ba11a0)
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: GCC-ALWAYS_INLINE-FIXME
10 
11 // TODO FMT This test should not require std::to_chars(floating-point)
12 // XFAIL: availability-fp_to_chars-missing
13 
14 // Tests whether a move only type can be formatted. This is required by
15 // P2418R2 "Add support for std::generator-like types to std::format"
16 
17 // <format>
18 
19 #include <format>
20 #include <cassert>
21 
22 #include "MoveOnly.h"
23 #include "make_string.h"
24 #include "test_macros.h"
25 
26 #ifndef TEST_HAS_NO_LOCALIZATION
27 #  include <locale>
28 #endif
29 
30 #define SV(S) MAKE_STRING_VIEW(CharT, S)
31 
32 template <class CharT>
33 struct std::formatter<MoveOnly, CharT> : std::formatter<int, CharT> {
34   auto format(const MoveOnly& m, auto& ctx) const -> decltype(ctx.out()) {
35     return std::formatter<int, CharT>::format(m.get(), ctx);
36   }
37 };
38 
39 template <class CharT>
40 static void test() {
41   MoveOnly m{10};
42   CharT buffer[10];
43 #ifndef TEST_HAS_NO_LOCALIZATION
44   std::locale loc;
45 #endif
46 
47   assert(std::format(SV("{}"), MoveOnly{}) == SV("1"));
48 
49   assert(std::format(SV("{}"), m) == SV("10"));
50   assert(m.get() == 10);
51 
52   assert(std::format(SV("{}"), std::move(m)) == SV("10"));
53   assert(m.get() == 10);
54 
55 #ifndef TEST_HAS_NO_LOCALIZATION
56   assert(std::format(loc, SV("{}"), MoveOnly{}) == SV("1"));
57 
58   assert(std::format(loc, SV("{}"), m) == SV("10"));
59   assert(m.get() == 10);
60 
61   assert(std::format(loc, SV("{}"), std::move(m)) == SV("10"));
62   assert(m.get() == 10);
63 #endif
64 
65   assert(std::format_to(buffer, SV("{}"), MoveOnly{}) == &buffer[1]);
66 
67   assert(std::format_to(buffer, SV("{}"), m) == &buffer[2]);
68   assert(m.get() == 10);
69 
70   assert(std::format_to(buffer, SV("{}"), std::move(m)) == &buffer[2]);
71   assert(m.get() == 10);
72 
73 #ifndef TEST_HAS_NO_LOCALIZATION
74   assert(std::format_to(buffer, loc, SV("{}"), MoveOnly{}) == &buffer[1]);
75 
76   assert(std::format_to(buffer, loc, SV("{}"), m) == &buffer[2]);
77   assert(m.get() == 10);
78 
79   assert(std::format_to(buffer, loc, SV("{}"), std::move(m)) == &buffer[2]);
80   assert(m.get() == 10);
81 #endif
82 
83   assert(std::format_to_n(buffer, 5, SV("{}"), MoveOnly{}).out == &buffer[1]);
84 
85   assert(std::format_to_n(buffer, 5, SV("{}"), m).out == &buffer[2]);
86   assert(m.get() == 10);
87 
88   assert(std::format_to_n(buffer, 5, SV("{}"), std::move(m)).out == &buffer[2]);
89   assert(m.get() == 10);
90 
91 #ifndef TEST_HAS_NO_LOCALIZATION
92   assert(std::format_to_n(buffer, 5, loc, SV("{}"), MoveOnly{}).out == &buffer[1]);
93 
94   assert(std::format_to_n(buffer, 5, loc, SV("{}"), m).out == &buffer[2]);
95   assert(m.get() == 10);
96 
97   assert(std::format_to_n(buffer, 5, loc, SV("{}"), std::move(m)).out == &buffer[2]);
98   assert(m.get() == 10);
99 #endif
100 
101   assert(std::formatted_size(SV("{}"), MoveOnly{}) == 1);
102 
103   assert(std::formatted_size(SV("{}"), m) == 2);
104   assert(m.get() == 10);
105 
106   assert(std::formatted_size(SV("{}"), std::move(m)) == 2);
107   assert(m.get() == 10);
108 
109 #ifndef TEST_HAS_NO_LOCALIZATION
110   assert(std::formatted_size(loc, SV("{}"), MoveOnly{}) == 1);
111 
112   assert(std::formatted_size(loc, SV("{}"), m) == 2);
113   assert(m.get() == 10);
114 
115   assert(std::formatted_size(loc, SV("{}"), std::move(m)) == 2);
116   assert(m.get() == 10);
117 #endif
118 }
119 
120 int main(int, char**) {
121   test<char>();
122 
123 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
124   test<wchar_t>();
125 #endif
126 
127   return 0;
128 }
129