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 // template<class charT, class traits, class Allocator>
12 //   basic_string<charT,traits,Allocator>
13 //   operator+(const basic_string<charT,traits,Allocator>& lhs, const charT* rhs); // constexpr since C++20
14 
15 // template<class charT, class traits, class Allocator>
16 //   basic_string<charT,traits,Allocator>&&
17 //   operator+(basic_string<charT,traits,Allocator>&& lhs, const charT* rhs); // constexpr since C++20
18 
19 #include <string>
20 #include <utility>
21 #include <cassert>
22 
23 #include "test_macros.h"
24 #include "min_allocator.h"
25 
26 template <class S>
27 TEST_CONSTEXPR_CXX20 void test0(const S& lhs, const typename S::value_type* rhs, const S& x) {
28   assert(lhs + rhs == x);
29 }
30 
31 #if TEST_STD_VER >= 11
32 template <class S>
33 TEST_CONSTEXPR_CXX20 void test1(S&& lhs, const typename S::value_type* rhs, const S& x) {
34   assert(std::move(lhs) + rhs == x);
35 }
36 #endif
37 
38 TEST_CONSTEXPR_CXX20 bool test() {
39   {
40     typedef std::string S;
41     test0(S(""), "", S(""));
42     test0(S(""), "12345", S("12345"));
43     test0(S(""), "1234567890", S("1234567890"));
44     test0(S(""), "12345678901234567890", S("12345678901234567890"));
45     test0(S("abcde"), "", S("abcde"));
46     test0(S("abcde"), "12345", S("abcde12345"));
47     test0(S("abcde"), "1234567890", S("abcde1234567890"));
48     test0(S("abcde"), "12345678901234567890", S("abcde12345678901234567890"));
49     test0(S("abcdefghij"), "", S("abcdefghij"));
50     test0(S("abcdefghij"), "12345", S("abcdefghij12345"));
51     test0(S("abcdefghij"), "1234567890", S("abcdefghij1234567890"));
52     test0(S("abcdefghij"), "12345678901234567890", S("abcdefghij12345678901234567890"));
53     test0(S("abcdefghijklmnopqrst"), "", S("abcdefghijklmnopqrst"));
54     test0(S("abcdefghijklmnopqrst"), "12345", S("abcdefghijklmnopqrst12345"));
55     test0(S("abcdefghijklmnopqrst"), "1234567890", S("abcdefghijklmnopqrst1234567890"));
56     test0(S("abcdefghijklmnopqrst"), "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
57   }
58 #if TEST_STD_VER >= 11
59   {
60     typedef std::string S;
61     test1(S(""), "", S(""));
62     test1(S(""), "12345", S("12345"));
63     test1(S(""), "1234567890", S("1234567890"));
64     test1(S(""), "12345678901234567890", S("12345678901234567890"));
65     test1(S("abcde"), "", S("abcde"));
66     test1(S("abcde"), "12345", S("abcde12345"));
67     test1(S("abcde"), "1234567890", S("abcde1234567890"));
68     test1(S("abcde"), "12345678901234567890", S("abcde12345678901234567890"));
69     test1(S("abcdefghij"), "", S("abcdefghij"));
70     test1(S("abcdefghij"), "12345", S("abcdefghij12345"));
71     test1(S("abcdefghij"), "1234567890", S("abcdefghij1234567890"));
72     test1(S("abcdefghij"), "12345678901234567890", S("abcdefghij12345678901234567890"));
73     test1(S("abcdefghijklmnopqrst"), "", S("abcdefghijklmnopqrst"));
74     test1(S("abcdefghijklmnopqrst"), "12345", S("abcdefghijklmnopqrst12345"));
75     test1(S("abcdefghijklmnopqrst"), "1234567890", S("abcdefghijklmnopqrst1234567890"));
76     test1(S("abcdefghijklmnopqrst"), "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
77   }
78   {
79     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char> > S;
80     test0(S(""), "", S(""));
81     test0(S(""), "12345", S("12345"));
82     test0(S(""), "1234567890", S("1234567890"));
83     test0(S(""), "12345678901234567890", S("12345678901234567890"));
84     test0(S("abcde"), "", S("abcde"));
85     test0(S("abcde"), "12345", S("abcde12345"));
86     test0(S("abcde"), "1234567890", S("abcde1234567890"));
87     test0(S("abcde"), "12345678901234567890", S("abcde12345678901234567890"));
88     test0(S("abcdefghij"), "", S("abcdefghij"));
89     test0(S("abcdefghij"), "12345", S("abcdefghij12345"));
90     test0(S("abcdefghij"), "1234567890", S("abcdefghij1234567890"));
91     test0(S("abcdefghij"), "12345678901234567890", S("abcdefghij12345678901234567890"));
92     test0(S("abcdefghijklmnopqrst"), "", S("abcdefghijklmnopqrst"));
93     test0(S("abcdefghijklmnopqrst"), "12345", S("abcdefghijklmnopqrst12345"));
94     test0(S("abcdefghijklmnopqrst"), "1234567890", S("abcdefghijklmnopqrst1234567890"));
95     test0(S("abcdefghijklmnopqrst"), "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
96 
97     test1(S(""), "", S(""));
98     test1(S(""), "12345", S("12345"));
99     test1(S(""), "1234567890", S("1234567890"));
100     test1(S(""), "12345678901234567890", S("12345678901234567890"));
101     test1(S("abcde"), "", S("abcde"));
102     test1(S("abcde"), "12345", S("abcde12345"));
103     test1(S("abcde"), "1234567890", S("abcde1234567890"));
104     test1(S("abcde"), "12345678901234567890", S("abcde12345678901234567890"));
105     test1(S("abcdefghij"), "", S("abcdefghij"));
106     test1(S("abcdefghij"), "12345", S("abcdefghij12345"));
107     test1(S("abcdefghij"), "1234567890", S("abcdefghij1234567890"));
108     test1(S("abcdefghij"), "12345678901234567890", S("abcdefghij12345678901234567890"));
109     test1(S("abcdefghijklmnopqrst"), "", S("abcdefghijklmnopqrst"));
110     test1(S("abcdefghijklmnopqrst"), "12345", S("abcdefghijklmnopqrst12345"));
111     test1(S("abcdefghijklmnopqrst"), "1234567890", S("abcdefghijklmnopqrst1234567890"));
112     test1(S("abcdefghijklmnopqrst"), "12345678901234567890", S("abcdefghijklmnopqrst12345678901234567890"));
113   }
114 #endif
115 
116   return true;
117 }
118 
119 int main(int, char**) {
120   test();
121 #if TEST_STD_VER > 17
122   static_assert(test());
123 #endif
124 
125   return 0;
126 }
127