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// UNSUPPORTED: c++03, c++11, c++14, c++17
10
11// <sstream>
12
13// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
14// class basic_stringbuf
15
16// basic_string_view<charT, traits> view() const noexcept;
17
18#include <sstream>
19#include <cassert>
20#include <type_traits>
21
22#include "make_string.h"
23#include "test_macros.h"
24
25#define STR(S) MAKE_STRING(CharT, S)
26#define SV(S) MAKE_STRING_VIEW(CharT, S)
27
28template <class CharT>
29struct my_char_traits : public std::char_traits<CharT> {};
30
31template <class CharT>
32static void test() {
33 std::basic_stringbuf<CharT> buf(STR("testing"));
34 static_assert(noexcept(buf.view()));
35 assert(buf.view() == SV("testing"));
36 buf.str(STR("another test"));
37 assert(buf.view() == SV("another test"));
38
39 std::basic_stringbuf<CharT> robuf(STR("foo"), std::ios_base::in);
40 assert(robuf.view() == SV("foo"));
41
42 std::basic_stringbuf<CharT> nbuf(STR("not used"), 0);
43 assert(nbuf.view() == std::basic_string_view<CharT>());
44
45 const std::basic_stringbuf<CharT> cbuf(STR("abc"));
46 static_assert(noexcept(cbuf.view()));
47 assert(cbuf.view() == SV("abc"));
48
49 std::basic_stringbuf<CharT, my_char_traits<CharT>> tbuf;
50 static_assert(std::is_same_v<decltype(tbuf.view()), std::basic_string_view<CharT, my_char_traits<CharT>>>);
51}
52
53struct StringBuf : std::stringbuf {
54 using basic_stringbuf::basic_stringbuf;
55 void public_setg(int a, int b, int c) {
56 char* p = eback();
57 this->setg(gbeg: p + a, gnext: p + b, gend: p + c);
58 }
59};
60
61static void test_altered_sequence_pointers() {
62 {
63 auto src = StringBuf("hello world", std::ios_base::in);
64 src.public_setg(a: 4, b: 6, c: 9);
65 std::stringbuf dest;
66 dest = std::move(src);
67 assert(dest.view() == dest.str());
68 LIBCPP_ASSERT(dest.view() == "o wor");
69 }
70 {
71 auto src = StringBuf("hello world", std::ios_base::in);
72 src.public_setg(a: 4, b: 6, c: 9);
73 std::stringbuf dest;
74 dest.swap(rhs&: src);
75 assert(dest.view() == dest.str());
76 LIBCPP_ASSERT(dest.view() == "o wor");
77 }
78}
79
80int main(int, char**) {
81 test<char>();
82#ifndef TEST_HAS_NO_WIDE_CHARACTERS
83 test<wchar_t>();
84#endif
85 test_altered_sequence_pointers();
86 return 0;
87}
88

source code of libcxx/test/std/input.output/string.streams/stringbuf/stringbuf.members/view.pass.cpp