129 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8// UNSUPPORTED: c++03, c++11, c++14, c++179 10// <span>11 12// template<class OtherElementType, size_t OtherExtent>13// constexpr span(const span<OtherElementType, OtherExtent>& s) noexcept;14//15// Remarks: This constructor shall not participate in overload resolution unless:16// Extent == dynamic_extent || Extent == OtherExtent is true, and17// OtherElementType(*)[] is convertible to ElementType(*)[].18 19#include <span>20#include <cassert>21#include <string>22 23#include "test_macros.h"24 25template <class T, std::size_t extent, size_t otherExtent>26std::span<T, extent> createImplicitSpan(std::span<T, otherExtent> s) {27 return {s}; // expected-error {{chosen constructor is explicit in copy-initialization}}28}29 30void checkCV() {31 // std::span< int> sp;32 std::span<const int> csp;33 std::span< volatile int> vsp;34 std::span<const volatile int> cvsp;35 36 // std::span< int, 0> sp0;37 std::span<const int, 0> csp0;38 std::span< volatile int, 0> vsp0;39 std::span<const volatile int, 0> cvsp0;40 41 // Try to remove const and/or volatile (dynamic -> dynamic)42 {43 std::span< int> s1{csp}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}44 std::span< int> s2{vsp}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}45 std::span< int> s3{cvsp}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}46 47 std::span<const int> s4{vsp};48 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}49 std::span<const int> s5{cvsp};50 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}51 52 std::span< volatile int> s6{csp};53 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}54 std::span< volatile int> s7{cvsp};55 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}56 }57 58 // Try to remove const and/or volatile (static -> static)59 {60 std::span< int, 0> s1{csp0}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}61 std::span< int, 0> s2{vsp0}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}62 std::span< int, 0> s3{cvsp0};63 // expected-error@-1 {{no matching constructor for initialization of 'std::span<int, 0>'}}64 65 std::span<const int, 0> s4{vsp0};66 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}67 std::span<const int, 0> s5{cvsp0};68 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}69 70 std::span< volatile int, 0> s6{csp0};71 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}72 std::span< volatile int, 0> s7{cvsp0};73 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}74 }75 76 // Try to remove const and/or volatile (static -> dynamic)77 {78 std::span< int> s1{csp0}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}79 std::span< int> s2{vsp0}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}80 std::span< int> s3{cvsp0}; // expected-error {{no matching constructor for initialization of 'std::span<int>'}}81 82 std::span<const int> s4{vsp0};83 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}84 std::span<const int> s5{cvsp0};85 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int>'}}86 87 std::span< volatile int> s6{csp0};88 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}89 std::span< volatile int> s7{cvsp0};90 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int>'}}91 }92 93 // Try to remove const and/or volatile (static -> static)94 {95 std::span< int, 0> s1{csp}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}96 std::span< int, 0> s2{vsp}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}97 std::span< int, 0> s3{cvsp}; // expected-error {{no matching constructor for initialization of 'std::span<int, 0>'}}98 99 std::span<const int, 0> s4{vsp};100 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}101 std::span<const int, 0> s5{cvsp};102 // expected-error@-1 {{no matching constructor for initialization of 'std::span<const int, 0>'}}103 104 std::span< volatile int, 0> s6{csp};105 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}106 std::span< volatile int, 0> s7{cvsp};107 // expected-error@-1 {{no matching constructor for initialization of 'std::span<volatile int, 0>'}}108 }109}110 111int main(int, char**) {112 std::span<int> sp;113 std::span<int, 0> sp0;114 115 std::span<float> s1{sp}; // expected-error {{no matching constructor for initialization of 'std::span<float>'}}116 std::span<float> s2{sp0}; // expected-error {{no matching constructor for initialization of 'std::span<float>'}}117 std::span<float, 0> s3{sp}; // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}118 std::span<float, 0> s4{sp0}; // expected-error {{no matching constructor for initialization of 'std::span<float, 0>'}}119 120 checkCV();121 122 // explicit constructor necessary123 {124 createImplicitSpan<int, 1>(sp);125 }126 127 return 0;128}129