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 10 // <string_view> 11 12 // template <class It, class End> 13 // constexpr basic_string_view(It begin, End end) 14 15 #include <string_view> 16 #include <cassert> 17 #include <iterator> 18 19 #include "make_string.h" 20 #include "test_iterators.h" 21 22 template<class It, class Sentinel, class CharT> 23 constexpr void test_construction(std::basic_string_view<CharT> val) { 24 auto sv = std::basic_string_view<CharT>(It(val.data()), Sentinel(It(val.data() + val.size()))); 25 assert(sv.data() == val.data()); 26 assert(sv.size() == val.size()); 27 } 28 29 template<class CharT> 30 constexpr void test_with_char() { 31 const auto val = MAKE_STRING_VIEW(CharT, "test"); 32 test_construction<CharT*, CharT*>(val); 33 test_construction<CharT*, const CharT*>(val); 34 test_construction<const CharT*, CharT*>(val); 35 test_construction<const CharT*, sized_sentinel<const CharT*>>(val); 36 test_construction<contiguous_iterator<const CharT*>, contiguous_iterator<const CharT*>>(val); 37 test_construction<contiguous_iterator<const CharT*>, sized_sentinel<contiguous_iterator<const CharT*>>>(val); 38 } 39 40 constexpr bool test() { 41 test_with_char<char>(); 42 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 43 test_with_char<wchar_t>(); 44 #endif 45 test_with_char<char8_t>(); 46 test_with_char<char16_t>(); 47 test_with_char<char32_t>(); 48 49 return true; 50 } 51 52 #ifndef TEST_HAS_NO_EXCEPTIONS 53 template<class CharT> 54 struct ThrowingSentinel { 55 friend bool operator==(const CharT*, ThrowingSentinel) noexcept { return true; } 56 friend std::iter_difference_t<const CharT*> operator-(const CharT*, ThrowingSentinel) noexcept { return {}; } 57 friend std::iter_difference_t<const CharT*> operator-(ThrowingSentinel, const CharT*) { throw 42; } 58 }; 59 60 template <class CharT> 61 void test_throwing() { 62 auto val = MAKE_STRING_VIEW(CharT, "test"); 63 try { 64 (void)std::basic_string_view<CharT>(val.data(), ThrowingSentinel<CharT>()); 65 assert(false); 66 } catch (int i) { 67 assert(i == 42); 68 } 69 } 70 71 void test_throwing() { 72 test_throwing<char>(); 73 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 74 test_throwing<wchar_t>(); 75 #endif 76 test_throwing<char8_t>(); 77 test_throwing<char16_t>(); 78 test_throwing<char32_t>(); 79 } 80 #endif 81 82 static_assert( std::is_constructible_v<std::string_view, const char*, char*>); 83 static_assert( std::is_constructible_v<std::string_view, char*, const char*>); 84 static_assert(!std::is_constructible_v<std::string_view, char*, void*>); // not a sentinel 85 static_assert(!std::is_constructible_v<std::string_view, signed char*, signed char*>); // wrong char type 86 static_assert(!std::is_constructible_v<std::string_view, random_access_iterator<char*>, random_access_iterator<char*>>); // not contiguous 87 static_assert( std::is_constructible_v<std::string_view, contiguous_iterator<char*>, contiguous_iterator<char*>>); 88 89 int main(int, char**) { 90 test(); 91 static_assert(test()); 92 93 #ifndef TEST_HAS_NO_EXCEPTIONS 94 test_throwing(); 95 #endif 96 97 return 0; 98 } 99