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 // UNSUPPORTED: c++03, c++11, c++14, c++17 9 // UNSUPPORTED: libcpp-no-concepts 10 11 // <string_view> 12 13 // template <class It, class End> 14 // constexpr basic_string_view(It begin, End end) 15 16 #include <string_view> 17 #include <cassert> 18 #include <iterator> 19 20 #include "make_string.h" 21 #include "test_iterators.h" 22 23 template<class CharT, class Sentinel> 24 constexpr void test() { 25 auto val = MAKE_STRING_VIEW(CharT, "test"); 26 auto sv = std::basic_string_view<CharT>(val.begin(), Sentinel(val.end())); 27 ASSERT_SAME_TYPE(decltype(sv), std::basic_string_view<CharT>); 28 assert(sv.size() == val.size()); 29 assert(sv.data() == val.data()); 30 } 31 32 constexpr bool test() { 33 test<char, char*>(); 34 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 35 test<wchar_t, wchar_t*>(); 36 #endif 37 test<char8_t, char8_t*>(); 38 test<char16_t, char16_t*>(); 39 test<char32_t, char32_t*>(); 40 test<char, const char*>(); 41 test<char, sized_sentinel<const char*>>(); 42 return true; 43 } 44 45 #ifndef TEST_HAS_NO_EXCEPTIONS 46 template<class CharT> 47 struct ThrowingSentinel { 48 friend bool operator==(const CharT*, ThrowingSentinel) noexcept { return true; } 49 friend std::iter_difference_t<const CharT*> operator-(const CharT*, ThrowingSentinel) noexcept { return {}; } 50 friend std::iter_difference_t<const CharT*> operator-(ThrowingSentinel, const CharT*) { throw 42; } 51 }; 52 53 template <class CharT> 54 void test_throwing() { 55 auto val = MAKE_STRING_VIEW(CharT, "test"); 56 try { 57 (void)std::basic_string_view<CharT>(val.begin(), ThrowingSentinel<CharT>()); 58 assert(false); 59 } catch (int i) { 60 assert(i == 42); 61 } 62 } 63 64 void test_throwing() { 65 test_throwing<char>(); 66 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 67 test_throwing<wchar_t>(); 68 #endif 69 test_throwing<char8_t>(); 70 test_throwing<char16_t>(); 71 test_throwing<char32_t>(); 72 } 73 #endif 74 75 static_assert( std::is_constructible_v<std::string_view, const char*, char*>); 76 static_assert( std::is_constructible_v<std::string_view, char*, const char*>); 77 static_assert(!std::is_constructible_v<std::string_view, char*, void*>); // not a sentinel 78 static_assert(!std::is_constructible_v<std::string_view, signed char*, signed char*>); // wrong char type 79 static_assert(!std::is_constructible_v<std::string_view, random_access_iterator<char*>, random_access_iterator<char*>>); // not contiguous 80 static_assert( std::is_constructible_v<std::string_view, contiguous_iterator<char*>, contiguous_iterator<char*>>); 81 82 int main(int, char**) { 83 test(); 84 static_assert(test()); 85 86 #ifndef TEST_HAS_NO_EXCEPTIONS 87 test_throwing(); 88 #endif 89 90 return 0; 91 } 92 93