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_filebuf
13
14// template <class charT, class traits>
15// void
16// swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y);
17
18#include <fstream>
19#include <cassert>
20#include "test_macros.h"
21#include "platform_support.h"
22
23int main(int, char**)
24{
25 std::string temp = get_temp_file_name();
26 {
27 std::filebuf f;
28 assert(f.open(temp.c_str(), std::ios_base::out | std::ios_base::in
29 | std::ios_base::trunc) != 0);
30 assert(f.is_open());
31 assert(f.sputn("123", 3) == 3);
32 f.pubseekoff(off: 1, way: std::ios_base::beg);
33 assert(f.sgetc() == '2');
34 std::filebuf f2;
35 swap(x&: f2, y&: f);
36 assert(!f.is_open());
37 assert(f2.is_open());
38 assert(f2.sgetc() == '2');
39 }
40 std::remove(filename: temp.c_str());
41
42 // lhs uses a small buffer, rhs is empty
43 {
44 std::filebuf f;
45 assert(f.open(temp.c_str(), std::ios_base::out | std::ios_base::in
46 | std::ios_base::trunc) != 0);
47 assert(f.is_open());
48 assert(f.sputn("123", 3) == 3);
49 f.pubseekoff(off: 1, way: std::ios_base::beg);
50 assert(f.sgetc() == '2');
51 std::filebuf f2;
52 swap(x&: f, y&: f2);
53 assert(!f.is_open());
54 assert(f2.is_open());
55 assert(f2.sgetc() == '2');
56 }
57 std::remove(filename: temp.c_str());
58
59 // neither lhs nor rhs use the small buffer
60 {
61 std::string tmpA = get_temp_file_name();
62 std::string tmpB = get_temp_file_name();
63
64 {
65 // currently the small buffer has size 8
66 std::ofstream sa(tmpA), sb(tmpB);
67 sa << "0123456789";
68 sb << "abcdefghij";
69 }
70
71 std::filebuf f1, f2;
72 assert(f1.open(tmpA, std::ios_base::in) != 0);
73 assert(f2.open(tmpB, std::ios_base::in) != 0);
74 assert(f1.sgetc() == '0');
75 assert(f2.sgetc() == 'a');
76
77 swap(x&: f1, y&: f2);
78
79 assert(f1.sgetc() == 'a');
80 assert(f2.sgetc() == '0');
81
82 std::remove(filename: tmpA.c_str());
83 std::remove(filename: tmpB.c_str());
84 }
85
86#ifndef TEST_HAS_NO_WIDE_CHARACTERS
87 {
88 std::wfilebuf f;
89 assert(f.open(temp.c_str(), std::ios_base::out | std::ios_base::in
90 | std::ios_base::trunc) != 0);
91 assert(f.is_open());
92 assert(f.sputn(L"123", 3) == 3);
93 f.pubseekoff(off: 1, way: std::ios_base::beg);
94 assert(f.sgetc() == L'2');
95 std::wfilebuf f2;
96 swap(x&: f2, y&: f);
97 assert(!f.is_open());
98 assert(f2.is_open());
99 assert(f2.sgetc() == L'2');
100 }
101 std::remove(filename: temp.c_str());
102#endif
103
104 return 0;
105}
106

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