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
28 template <class CharT>
29 struct my_char_traits : public std::char_traits<CharT> {};
30
31 template <class CharT>
test()32 static 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
53 struct StringBuf : std::stringbuf {
54 using basic_stringbuf::basic_stringbuf;
public_setgStringBuf55 void public_setg(int a, int b, int c) {
56 char* p = eback();
57 this->setg(p + a, p + b, p + c);
58 }
59 };
60
test_altered_sequence_pointers()61 static void test_altered_sequence_pointers() {
62 {
63 auto src = StringBuf("hello world", std::ios_base::in);
64 src.public_setg(4, 6, 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(4, 6, 9);
73 std::stringbuf dest;
74 dest.swap(src);
75 assert(dest.view() == dest.str());
76 LIBCPP_ASSERT(dest.view() == "o wor");
77 }
78 }
79
main(int,char **)80 int 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