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 // <string>
10 
11 // iterator erase(const_iterator p); // constexpr since C++20
12 
13 #include <string>
14 #include <cassert>
15 
16 #include "test_macros.h"
17 #include "min_allocator.h"
18 
19 template <class S>
20 TEST_CONSTEXPR_CXX20 void
test(S s,typename S::difference_type pos,S expected)21 test(S s, typename S::difference_type pos, S expected)
22 {
23     typename S::const_iterator p = s.begin() + pos;
24     typename S::iterator i = s.erase(p);
25     LIBCPP_ASSERT(s.__invariants());
26     assert(s[s.size()] == typename S::value_type());
27     assert(s == expected);
28     assert(i - s.begin() == pos);
29 }
30 
test()31 TEST_CONSTEXPR_CXX20 bool test() {
32   {
33     typedef std::string S;
34     test(S("abcde"), 0, S("bcde"));
35     test(S("abcde"), 1, S("acde"));
36     test(S("abcde"), 2, S("abde"));
37     test(S("abcde"), 4, S("abcd"));
38     test(S("abcdefghij"), 0, S("bcdefghij"));
39     test(S("abcdefghij"), 1, S("acdefghij"));
40     test(S("abcdefghij"), 5, S("abcdeghij"));
41     test(S("abcdefghij"), 9, S("abcdefghi"));
42     test(S("abcdefghijklmnopqrst"), 0, S("bcdefghijklmnopqrst"));
43     test(S("abcdefghijklmnopqrst"), 1, S("acdefghijklmnopqrst"));
44     test(S("abcdefghijklmnopqrst"), 10, S("abcdefghijlmnopqrst"));
45     test(S("abcdefghijklmnopqrst"), 19, S("abcdefghijklmnopqrs"));
46   }
47 #if TEST_STD_VER >= 11
48   {
49     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
50     test(S("abcde"), 0, S("bcde"));
51     test(S("abcde"), 1, S("acde"));
52     test(S("abcde"), 2, S("abde"));
53     test(S("abcde"), 4, S("abcd"));
54     test(S("abcdefghij"), 0, S("bcdefghij"));
55     test(S("abcdefghij"), 1, S("acdefghij"));
56     test(S("abcdefghij"), 5, S("abcdeghij"));
57     test(S("abcdefghij"), 9, S("abcdefghi"));
58     test(S("abcdefghijklmnopqrst"), 0, S("bcdefghijklmnopqrst"));
59     test(S("abcdefghijklmnopqrst"), 1, S("acdefghijklmnopqrst"));
60     test(S("abcdefghijklmnopqrst"), 10, S("abcdefghijlmnopqrst"));
61     test(S("abcdefghijklmnopqrst"), 19, S("abcdefghijklmnopqrs"));
62   }
63 #endif
64 
65   return true;
66 }
67 
main(int,char **)68 int main(int, char**)
69 {
70   test();
71 #if TEST_STD_VER > 17
72   static_assert(test());
73 #endif
74 
75   return 0;
76 }
77