1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <fstream>
11 
12 // template <class charT, class traits = char_traits<charT> >
13 // class basic_ofstream
14 
15 // template <class charT, class traits>
16 //   void swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
17 
18 #include <fstream>
19 #include <utility>
20 #include <cassert>
21 #include "platform_support.h"
22 
get_temp_file_names()23 std::pair<std::string, std::string> get_temp_file_names() {
24   std::pair<std::string, std::string> names;
25   names.first = get_temp_file_name();
26 
27   // Create the file so the next call to `get_temp_file_name()` doesn't
28   // return the same file.
29   std::FILE *fd1 = std::fopen(names.first.c_str(), "w");
30 
31   names.second = get_temp_file_name();
32   assert(names.first != names.second);
33 
34   std::fclose(fd1);
35   std::remove(names.first.c_str());
36 
37   return names;
38 }
39 
main()40 int main()
41 {
42     std::pair<std::string, std::string> temp_files = get_temp_file_names();
43     std::string& temp1 = temp_files.first;
44     std::string& temp2 = temp_files.second;
45     assert(temp1 != temp2);
46     {
47         std::ofstream fs1(temp1.c_str());
48         std::ofstream fs2(temp2.c_str());
49         fs1 << 3.25;
50         fs2 << 4.5;
51         swap(fs1, fs2);
52         fs1 << ' ' << 3.25;
53         fs2 << ' ' << 4.5;
54     }
55     {
56         std::ifstream fs(temp1.c_str());
57         double x = 0;
58         fs >> x;
59         assert(x == 3.25);
60         fs >> x;
61         assert(x == 4.5);
62     }
63     std::remove(temp1.c_str());
64     {
65         std::ifstream fs(temp2.c_str());
66         double x = 0;
67         fs >> x;
68         assert(x == 4.5);
69         fs >> x;
70         assert(x == 3.25);
71     }
72     std::remove(temp2.c_str());
73     {
74         std::wofstream fs1(temp1.c_str());
75         std::wofstream fs2(temp2.c_str());
76         fs1 << 3.25;
77         fs2 << 4.5;
78         swap(fs1, fs2);
79         fs1 << ' ' << 3.25;
80         fs2 << ' ' << 4.5;
81     }
82     {
83         std::wifstream fs(temp1.c_str());
84         double x = 0;
85         fs >> x;
86         assert(x == 3.25);
87         fs >> x;
88         assert(x == 4.5);
89     }
90     std::remove(temp1.c_str());
91     {
92         std::wifstream fs(temp2.c_str());
93         double x = 0;
94         fs >> x;
95         assert(x == 4.5);
96         fs >> x;
97         assert(x == 3.25);
98     }
99     std::remove(temp2.c_str());
100 }
101