xref: /llvm-project/libcxx/test/std/strings/basic.string/string.modifiers/string_assign/iterator.pass.cpp (revision bd5d0fee9bbb3762ff26538f03d59926f5635c78)
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 InputIterator>
12 //   basic_string& assign(InputIterator first, InputIterator last); // constexpr since C++20
13 
14 #include <string>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 #include "test_iterators.h"
19 #include "min_allocator.h"
20 
21 template <class S, class It>
22 TEST_CONSTEXPR_CXX20 void
23 test(S s, It first, It last, S expected)
24 {
25     s.assign(first, last);
26     LIBCPP_ASSERT(s.__invariants());
27     assert(s == expected);
28 }
29 
30 #ifndef TEST_HAS_NO_EXCEPTIONS
31 struct Widget { operator char() const { throw 42; } };
32 
33 template <class S, class It>
34 void
35 test_exceptions(S s, It first, It last)
36 {
37     S original = s;
38     typename S::iterator begin = s.begin();
39     typename S::iterator end = s.end();
40 
41     try {
42         s.assign(first, last);
43         assert(false);
44     } catch (...) {}
45 
46     // Part of "no effects" is that iterators and pointers
47     // into the string must not have been invalidated.
48     LIBCPP_ASSERT(s.__invariants());
49     assert(s == original);
50     assert(s.begin() == begin);
51     assert(s.end() == end);
52 }
53 #endif
54 
55 template <class S>
56 TEST_CONSTEXPR_CXX20 void test_string() {
57   const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
58   test(S(), s, s, S());
59   test(S(), s, s+1, S("A"));
60   test(S(), s, s+10, S("ABCDEFGHIJ"));
61   test(S(), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
62 
63   test(S("12345"), s, s, S());
64   test(S("12345"), s, s+1, S("A"));
65   test(S("12345"), s, s+10, S("ABCDEFGHIJ"));
66   test(S("12345"), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
67 
68   test(S("1234567890"), s, s, S());
69   test(S("1234567890"), s, s+1, S("A"));
70   test(S("1234567890"), s, s+10, S("ABCDEFGHIJ"));
71   test(S("1234567890"), s, s+52, S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
72 
73   test(S("12345678901234567890"), s, s, S());
74   test(S("12345678901234567890"), s, s+1, S("A"));
75   test(S("12345678901234567890"), s, s+10, S("ABCDEFGHIJ"));
76   test(S("12345678901234567890"), s, s+52,
77       S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
78 
79   test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s), S());
80   test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1), S("A"));
81   test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
82       S("ABCDEFGHIJ"));
83   test(S(), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
84       S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
85 
86   test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
87       S());
88   test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
89       S("A"));
90   test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
91       S("ABCDEFGHIJ"));
92   test(S("12345"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
93       S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
94 
95   test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
96       S());
97   test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
98       S("A"));
99   test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
100       S("ABCDEFGHIJ"));
101   test(S("1234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
102       S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
103 
104   test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s),
105       S());
106   test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+1),
107       S("A"));
108   test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+10),
109       S("ABCDEFGHIJ"));
110   test(S("12345678901234567890"), cpp17_input_iterator<const char*>(s), cpp17_input_iterator<const char*>(s+52),
111       S("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"));
112 }
113 
114 TEST_CONSTEXPR_CXX20 bool test() {
115   test_string<std::string>();
116 #if TEST_STD_VER >= 11
117   test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
118 #endif
119 
120 #ifndef TEST_HAS_NO_EXCEPTIONS
121   if (!TEST_IS_CONSTANT_EVALUATED) { // test iterator operations that throw
122     typedef std::string S;
123     typedef ThrowingIterator<char> TIter;
124     typedef cpp17_input_iterator<TIter> IIter;
125     const char* s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
126     test_exceptions(S(), IIter(TIter(s, s+10, 4, TIter::TAIncrement)), IIter(TIter()));
127     test_exceptions(S(), IIter(TIter(s, s+10, 5, TIter::TADereference)), IIter(TIter()));
128     test_exceptions(S(), IIter(TIter(s, s+10, 6, TIter::TAComparison)), IIter(TIter()));
129 
130     test_exceptions(S(), TIter(s, s+10, 4, TIter::TAIncrement), TIter());
131     test_exceptions(S(), TIter(s, s+10, 5, TIter::TADereference), TIter());
132     test_exceptions(S(), TIter(s, s+10, 6, TIter::TAComparison), TIter());
133 
134     Widget w[100];
135     test_exceptions(S(), w, w+100);
136   }
137 #endif
138 
139   { // test assigning to self
140     typedef std::string S;
141     S s_short = "123/";
142     S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
143 
144     s_short.assign(s_short.begin(), s_short.end());
145     assert(s_short == "123/");
146     s_short.assign(s_short.begin() + 2, s_short.end());
147     assert(s_short == "3/");
148 
149     s_long.assign(s_long.begin(), s_long.end());
150     assert(s_long == "Lorem ipsum dolor sit amet, consectetur/");
151 
152     s_long.assign(s_long.begin() + 30, s_long.end());
153     assert(s_long == "nsectetur/");
154   }
155 
156   { // test assigning a different type
157     typedef std::string S;
158     const std::uint8_t p[] = "ABCD";
159 
160     S s;
161     s.assign(p, p + 4);
162     assert(s == "ABCD");
163   }
164 
165   { // regression-test assigning to self in sneaky ways
166     std::string sneaky = "hello";
167     sneaky.resize(sneaky.capacity(), 'x');
168     std::string expected = sneaky + std::string(1, '\0');
169     test(sneaky, sneaky.data(), sneaky.data() + sneaky.size() + 1, expected);
170   }
171   return true;
172 }
173 
174 int main(int, char**)
175 {
176   test();
177 #if TEST_STD_VER > 17
178   static_assert(test());
179 #endif
180 
181     return 0;
182 }
183