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// <ostream>
10
11// template <class charT, class traits = char_traits<charT> >
12// class basic_ostream;
13
14// template<class char, class traits>
15// basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>& out, char c);
16
17#include <ostream>
18#include <cassert>
19
20#include "test_macros.h"
21
22template <class CharT>
23class testbuf
24 : public std::basic_streambuf<CharT>
25{
26 typedef std::basic_streambuf<CharT> base;
27 std::basic_string<CharT> str_;
28public:
29 testbuf()
30 {
31 }
32
33 std::basic_string<CharT> str() const
34 {return std::basic_string<CharT>(base::pbase(), base::pptr());}
35
36protected:
37
38 virtual typename base::int_type
39 overflow(typename base::int_type ch = base::traits_type::eof())
40 {
41 if (ch != base::traits_type::eof())
42 {
43 int n = static_cast<int>(str_.size());
44 str_.push_back(static_cast<CharT>(ch));
45 str_.resize(str_.capacity());
46 base::setp(const_cast<CharT*>(str_.data()),
47 const_cast<CharT*>(str_.data() + str_.size()));
48 base::pbump(n+1);
49 }
50 return ch;
51 }
52};
53
54int main(int, char**)
55{
56 {
57 std::ostream os((std::streambuf*)0);
58 char c = 'a';
59 os << c;
60 assert(os.bad());
61 assert(os.fail());
62 }
63 {
64 testbuf<char> sb;
65 std::ostream os(&sb);
66 char c = 'a';
67 os << c;
68 assert(sb.str() == "a");
69 }
70 {
71 testbuf<char> sb;
72 std::ostream os(&sb);
73 os.width(wide: 5);
74 char c = 'a';
75 os << c;
76 assert(sb.str() == " a");
77 assert(os.width() == 0);
78 }
79 {
80 testbuf<char> sb;
81 std::ostream os(&sb);
82 os.width(wide: 5);
83 std::left(base&: os);
84 char c = 'a';
85 os << c;
86 assert(sb.str() == "a ");
87 assert(os.width() == 0);
88 }
89
90 return 0;
91}
92

source code of libcxx/test/std/input.output/iostream.format/output.streams/ostream.formatted/ostream.inserters.character/char.pass.cpp