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 It, class Sentinel, class CharT> 24 constexpr void test_construction(std::basic_string_view<CharT> val) { 25 auto sv = std::basic_string_view<CharT>(It(val.data()), Sentinel(It(val.data() + val.size()))); 26 assert(sv.data() == val.data()); 27 assert(sv.size() == val.size()); 28 } 29 30 template<class CharT> 31 constexpr void test_with_char() { 32 const auto val = MAKE_STRING_VIEW(CharT, "test"); 33 test_construction<CharT*, CharT*>(val); 34 test_construction<CharT*, const CharT*>(val); 35 test_construction<const CharT*, CharT*>(val); 36 test_construction<const CharT*, sized_sentinel<const CharT*>>(val); 37 test_construction<contiguous_iterator<const CharT*>, contiguous_iterator<const CharT*>>(val); 38 test_construction<contiguous_iterator<const CharT*>, sized_sentinel<contiguous_iterator<const CharT*>>>(val); 39 } 40 41 constexpr bool test() { 42 test_with_char<char>(); 43 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 44 test_with_char<wchar_t>(); 45 #endif 46 test_with_char<char8_t>(); 47 test_with_char<char16_t>(); 48 test_with_char<char32_t>(); 49 50 return true; 51 } 52 53 #ifndef TEST_HAS_NO_EXCEPTIONS 54 template<class CharT> 55 struct ThrowingSentinel { 56 friend bool operator==(const CharT*, ThrowingSentinel) noexcept { return true; } 57 friend std::iter_difference_t<const CharT*> operator-(const CharT*, ThrowingSentinel) noexcept { return {}; } 58 friend std::iter_difference_t<const CharT*> operator-(ThrowingSentinel, const CharT*) { throw 42; } 59 }; 60 61 template <class CharT> 62 void test_throwing() { 63 auto val = MAKE_STRING_VIEW(CharT, "test"); 64 try { 65 (void)std::basic_string_view<CharT>(val.data(), ThrowingSentinel<CharT>()); 66 assert(false); 67 } catch (int i) { 68 assert(i == 42); 69 } 70 } 71 72 void test_throwing() { 73 test_throwing<char>(); 74 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 75 test_throwing<wchar_t>(); 76 #endif 77 test_throwing<char8_t>(); 78 test_throwing<char16_t>(); 79 test_throwing<char32_t>(); 80 } 81 #endif 82 83 static_assert( std::is_constructible_v<std::string_view, const char*, char*>); 84 static_assert( std::is_constructible_v<std::string_view, char*, const char*>); 85 static_assert(!std::is_constructible_v<std::string_view, char*, void*>); // not a sentinel 86 static_assert(!std::is_constructible_v<std::string_view, signed char*, signed char*>); // wrong char type 87 static_assert(!std::is_constructible_v<std::string_view, random_access_iterator<char*>, random_access_iterator<char*>>); // not contiguous 88 static_assert( std::is_constructible_v<std::string_view, contiguous_iterator<char*>, contiguous_iterator<char*>>); 89 90 int main(int, char**) { 91 test(); 92 static_assert(test()); 93 94 #ifndef TEST_HAS_NO_EXCEPTIONS 95 test_throwing(); 96 #endif 97 98 return 0; 99 } 100