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<charT, traits, Allocator> str() &&;
17 
18 #include <sstream>
19 #include <cassert>
20 
21 #include "make_string.h"
22 #include "test_macros.h"
23 
24 #define STR(S) MAKE_STRING(CharT, S)
25 
26 template <class CharT>
test()27 static void test() {
28   {
29     std::basic_stringbuf<CharT> buf(STR("testing"));
30     std::basic_string<CharT> s = std::move(buf).str();
31     assert(s == STR("testing"));
32     assert(buf.view().empty());
33   }
34   {
35     std::basic_stringbuf<CharT> buf;
36     std::basic_string<CharT> s = std::move(buf).str();
37     assert(s.empty());
38     assert(buf.view().empty());
39   }
40   {
41     std::basic_stringbuf<CharT> buf(STR("a very long string that exceeds the small string optimization buffer length"));
42     const CharT* p             = buf.view().data();
43     std::basic_string<CharT> s = std::move(buf).str();
44     assert(s.data() == p); // the allocation was pilfered
45     assert(buf.view().empty());
46   }
47 }
48 
49 struct StringBuf : std::stringbuf {
50   using basic_stringbuf::basic_stringbuf;
public_setgStringBuf51   void public_setg(int a, int b, int c) {
52     char* p = eback();
53     this->setg(p + a, p + b, p + c);
54   }
55 };
56 
test_altered_sequence_pointers()57 static void test_altered_sequence_pointers() {
58   {
59     auto src = StringBuf("hello world", std::ios_base::in);
60     src.public_setg(4, 6, 9);
61     std::stringbuf dest;
62     dest             = std::move(src);
63     std::string view = std::string(dest.view());
64     std::string str  = std::move(dest).str();
65     assert(view == str);
66     LIBCPP_ASSERT(str == "o wor");
67     assert(dest.str().empty());
68     assert(dest.view().empty());
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     std::string view = std::string(dest.view());
76     std::string str  = std::move(dest).str();
77     assert(view == str);
78     LIBCPP_ASSERT(str == "o wor");
79     assert(dest.str().empty());
80     assert(dest.view().empty());
81   }
82 }
83 
main(int,char **)84 int main(int, char**) {
85   test<char>();
86 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
87   test<wchar_t>();
88 #endif
89   test_altered_sequence_pointers();
90   return 0;
91 }
92