xref: /llvm-project/libcxx/test/std/containers/sequences/vector/vector.modifiers/assign_range.pass.cpp (revision 733a98db4a264f474564cc2064b8862dedd8458f)
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, c++20
10 // ADDITIONAL_COMPILE_FLAGS(has-fconstexpr-steps): -fconstexpr-steps=2000000
11 
12 // template<container-compatible-range<T> R>
13 //   constexpr void assign_range(R&& rg); // C++23
14 
15 #include <sstream>
16 #include <vector>
17 
18 #include "../../insert_range_sequence_containers.h"
19 #include "asan_testing.h"
20 #include "test_macros.h"
21 
22 // Tested cases:
23 // - different kinds of assignments (assigning an {empty/one-element/mid-sized/long range} to an
24 //   {empty/one-element/full} container);
25 // - assigning move-only elements;
26 // - an exception is thrown when copying the elements or when allocating new elements.
27 constexpr bool test() {
28   static_assert(test_constraints_assign_range<std::vector, int, double>());
29 
30   for_all_iterators_and_allocators<int, const int*>([]<class Iter, class Sent, class Alloc>() {
31     test_sequence_assign_range<std::vector<int, Alloc>, Iter, Sent>([]([[maybe_unused]] auto&& c) {
32       LIBCPP_ASSERT(c.__invariants());
33       LIBCPP_ASSERT(is_contiguous_container_asan_correct(c));
34     });
35   });
36   test_sequence_assign_range_move_only<std::vector>();
37 
38   { // Vector may or may not need to reallocate because of the assignment -- make sure to test both cases.
39     { // Ensure reallocation happens.
40       int in[] = {-1, -2, -3, -4, -5, -6, -7, -8, -9, -10};
41       std::vector<int> v = {1, 2, 3, 4, 5, 6, 7, 8};
42       v.shrink_to_fit();
43       assert(v.capacity() < v.size() + std::ranges::size(in));
44 
45       v.assign_range(in);
46       assert(std::ranges::equal(v, in));
47     }
48 
49     { // Ensure no reallocation happens -- the input range is shorter than the vector.
50       int in[] = {-1, -2, -3, -4, -5};
51       std::vector<int> v = {1, 2, 3, 4, 5, 6, 7, 8};
52 
53       v.assign_range(in);
54       assert(std::ranges::equal(v, in));
55     }
56 
57     { // Ensure no reallocation happens -- the input range is longer than the vector but within capacity.
58       int in[] = {-1, -2, -3, -4, -5, -6, -7, -8};
59       std::vector<int> v = {1, 2, 3, 4, 5};
60       v.reserve(std::ranges::size(in));
61       assert(v.capacity() >= std::ranges::size(in));
62 
63       v.assign_range(in);
64       assert(std::ranges::equal(v, in));
65     }
66 
67     { // Ensure input-only sized ranges are accepted.
68       using input_iter = cpp20_input_iterator<const int*>;
69       const int in[]{1, 2, 3, 4};
70       std::vector<int> v;
71       v.assign_range(std::views::counted(input_iter{std::ranges::begin(in)}, std::ranges::ssize(in)));
72       assert(std::ranges::equal(v, std::vector<int>{1, 2, 3, 4}));
73     }
74   }
75 
76   return true;
77 }
78 
79 #ifndef TEST_HAS_NO_LOCALIZATION
80 void test_counted_istream_view() {
81   std::istringstream is{"1 2 3 4"};
82   auto vals = std::views::istream<int>(is);
83   std::vector<int> v;
84   v.assign_range(std::views::counted(vals.begin(), 3));
85   assert(v == (std::vector{1, 2, 3}));
86 }
87 #endif
88 
89 int main(int, char**) {
90   test();
91   static_assert(test());
92 
93   test_assign_range_exception_safety_throwing_copy<std::vector>();
94   test_assign_range_exception_safety_throwing_allocator<std::vector, int>();
95 
96 #ifndef TEST_HAS_NO_LOCALIZATION
97   test_counted_istream_view();
98 #endif
99 
100   return 0;
101 }
102