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// <fstream>
10
11// template <class charT, class traits = char_traits<charT> >
12// class basic_fstream
13
14// template <class charT, class traits>
15// void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
16
17#include <fstream>
18#include <utility>
19#include <cassert>
20#include "test_macros.h"
21#include "platform_support.h"
22
23
24std::pair<std::string, std::string> get_temp_file_names() {
25 std::pair<std::string, std::string> names;
26 names.first = get_temp_file_name();
27
28 // Create the file so the next call to `get_temp_file_name()` doesn't
29 // return the same file.
30 std::FILE *fd1 = std::fopen(filename: names.first.c_str(), modes: "w");
31
32 names.second = get_temp_file_name();
33 assert(names.first != names.second);
34
35 std::fclose(stream: fd1);
36 std::remove(filename: names.first.c_str());
37
38 return names;
39}
40
41int main(int, char**)
42{
43 std::pair<std::string, std::string> temp_files = get_temp_file_names();
44 std::string& temp1 = temp_files.first;
45 std::string& temp2 = temp_files.second;
46 assert(temp1 != temp2);
47 {
48 std::fstream fs1(temp1.c_str(), std::ios_base::in | std::ios_base::out
49 | std::ios_base::trunc);
50 std::fstream fs2(temp2.c_str(), std::ios_base::in | std::ios_base::out
51 | std::ios_base::trunc);
52 fs1 << 1 << ' ' << 2;
53 fs2 << 2 << ' ' << 1;
54 fs1.seekg(0);
55 swap(x&: fs1, y&: fs2);
56 fs1.seekg(0);
57 int i;
58 fs1 >> i;
59 assert(i == 2);
60 fs1 >> i;
61 assert(i == 1);
62 i = 0;
63 fs2 >> i;
64 assert(i == 1);
65 fs2 >> i;
66 assert(i == 2);
67 }
68 std::remove(filename: temp1.c_str());
69 std::remove(filename: temp2.c_str());
70
71#ifndef TEST_HAS_NO_WIDE_CHARACTERS
72 {
73 std::wfstream fs1(temp1.c_str(), std::ios_base::in | std::ios_base::out
74 | std::ios_base::trunc);
75 std::wfstream fs2(temp2.c_str(), std::ios_base::in | std::ios_base::out
76 | std::ios_base::trunc);
77 fs1 << 1 << ' ' << 2;
78 fs2 << 2 << ' ' << 1;
79 fs1.seekg(0);
80 swap(x&: fs1, y&: fs2);
81 fs1.seekg(0);
82 int i;
83 fs1 >> i;
84 assert(i == 2);
85 fs1 >> i;
86 assert(i == 1);
87 i = 0;
88 fs2 >> i;
89 assert(i == 1);
90 fs2 >> i;
91 assert(i == 2);
92 }
93 std::remove(filename: temp1.c_str());
94 std::remove(filename: temp2.c_str());
95#endif
96
97 return 0;
98}
99

source code of libcxx/test/std/input.output/file.streams/fstreams/fstream.assign/nonmember_swap.pass.cpp