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 charT* lhs, const basic_string<charT,traits,Allocator>& rhs); // constexpr since C++20
14 
15 // template<class charT, class traits, class Allocator>
16 //   basic_string<charT,traits,Allocator>&&
17 //   operator+(const charT* lhs, basic_string<charT,traits,Allocator>&& 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 typename S::value_type* lhs, const S& 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(const typename S::value_type* lhs, S&& rhs, const S& x) {
34   assert(lhs + std::move(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("abcde", S(""), S("abcde"));
46     test0("abcde", S("12345"), S("abcde12345"));
47     test0("abcde", S("1234567890"), S("abcde1234567890"));
48     test0("abcde", S("12345678901234567890"), S("abcde12345678901234567890"));
49     test0("abcdefghij", S(""), S("abcdefghij"));
50     test0("abcdefghij", S("12345"), S("abcdefghij12345"));
51     test0("abcdefghij", S("1234567890"), S("abcdefghij1234567890"));
52     test0("abcdefghij", S("12345678901234567890"), S("abcdefghij12345678901234567890"));
53     test0("abcdefghijklmnopqrst", S(""), S("abcdefghijklmnopqrst"));
54     test0("abcdefghijklmnopqrst", S("12345"), S("abcdefghijklmnopqrst12345"));
55     test0("abcdefghijklmnopqrst", S("1234567890"), S("abcdefghijklmnopqrst1234567890"));
56     test0("abcdefghijklmnopqrst", S("12345678901234567890"), S("abcdefghijklmnopqrst12345678901234567890"));
57   }
58 
59 #if TEST_STD_VER >= 11
60   {
61     typedef std::string S;
62     test1("", S(""), S(""));
63     test1("", S("12345"), S("12345"));
64     test1("", S("1234567890"), S("1234567890"));
65     test1("", S("12345678901234567890"), S("12345678901234567890"));
66     test1("abcde", S(""), S("abcde"));
67     test1("abcde", S("12345"), S("abcde12345"));
68     test1("abcde", S("1234567890"), S("abcde1234567890"));
69     test1("abcde", S("12345678901234567890"), S("abcde12345678901234567890"));
70     test1("abcdefghij", S(""), S("abcdefghij"));
71     test1("abcdefghij", S("12345"), S("abcdefghij12345"));
72     test1("abcdefghij", S("1234567890"), S("abcdefghij1234567890"));
73     test1("abcdefghij", S("12345678901234567890"), S("abcdefghij12345678901234567890"));
74     test1("abcdefghijklmnopqrst", S(""), S("abcdefghijklmnopqrst"));
75     test1("abcdefghijklmnopqrst", S("12345"), S("abcdefghijklmnopqrst12345"));
76     test1("abcdefghijklmnopqrst", S("1234567890"), S("abcdefghijklmnopqrst1234567890"));
77     test1("abcdefghijklmnopqrst", S("12345678901234567890"), S("abcdefghijklmnopqrst12345678901234567890"));
78   }
79   {
80     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char> > S;
81     test0("", S(""), S(""));
82     test0("", S("12345"), S("12345"));
83     test0("", S("1234567890"), S("1234567890"));
84     test0("", S("12345678901234567890"), S("12345678901234567890"));
85     test0("abcde", S(""), S("abcde"));
86     test0("abcde", S("12345"), S("abcde12345"));
87     test0("abcde", S("1234567890"), S("abcde1234567890"));
88     test0("abcde", S("12345678901234567890"), S("abcde12345678901234567890"));
89     test0("abcdefghij", S(""), S("abcdefghij"));
90     test0("abcdefghij", S("12345"), S("abcdefghij12345"));
91     test0("abcdefghij", S("1234567890"), S("abcdefghij1234567890"));
92     test0("abcdefghij", S("12345678901234567890"), S("abcdefghij12345678901234567890"));
93     test0("abcdefghijklmnopqrst", S(""), S("abcdefghijklmnopqrst"));
94     test0("abcdefghijklmnopqrst", S("12345"), S("abcdefghijklmnopqrst12345"));
95     test0("abcdefghijklmnopqrst", S("1234567890"), S("abcdefghijklmnopqrst1234567890"));
96     test0("abcdefghijklmnopqrst", S("12345678901234567890"), S("abcdefghijklmnopqrst12345678901234567890"));
97 
98     test1("", S(""), S(""));
99     test1("", S("12345"), S("12345"));
100     test1("", S("1234567890"), S("1234567890"));
101     test1("", S("12345678901234567890"), S("12345678901234567890"));
102     test1("abcde", S(""), S("abcde"));
103     test1("abcde", S("12345"), S("abcde12345"));
104     test1("abcde", S("1234567890"), S("abcde1234567890"));
105     test1("abcde", S("12345678901234567890"), S("abcde12345678901234567890"));
106     test1("abcdefghij", S(""), S("abcdefghij"));
107     test1("abcdefghij", S("12345"), S("abcdefghij12345"));
108     test1("abcdefghij", S("1234567890"), S("abcdefghij1234567890"));
109     test1("abcdefghij", S("12345678901234567890"), S("abcdefghij12345678901234567890"));
110     test1("abcdefghijklmnopqrst", S(""), S("abcdefghijklmnopqrst"));
111     test1("abcdefghijklmnopqrst", S("12345"), S("abcdefghijklmnopqrst12345"));
112     test1("abcdefghijklmnopqrst", S("1234567890"), S("abcdefghijklmnopqrst1234567890"));
113     test1("abcdefghijklmnopqrst", S("12345678901234567890"), S("abcdefghijklmnopqrst12345678901234567890"));
114   }
115 #endif
116 
117   return true;
118 }
119 
120 int main(int, char**) {
121   test();
122 #if TEST_STD_VER > 17
123   static_assert(test());
124 #endif
125 
126   return 0;
127 }
128