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

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