1//===----------------------------------------------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is dual licensed under the MIT and the University of Illinois Open 6// Source Licenses. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10// <memory> 11 12// template <class T> struct owner_less; 13// 14// template <class T> 15// struct owner_less<shared_ptr<T> > 16// : binary_function<shared_ptr<T>, shared_ptr<T>, bool> 17// { 18// typedef bool result_type; 19// bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept; 20// bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept; 21// bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept; 22// }; 23// 24// template <class T> 25// struct owner_less<weak_ptr<T> > 26// : binary_function<weak_ptr<T>, weak_ptr<T>, bool> 27// { 28// typedef bool result_type; 29// bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept; 30// bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept; 31// bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept; 32// }; 33// 34// Added in C++17 35// template<> struct owner_less<void> 36// { 37// template<class T, class U> 38// bool operator()(shared_ptr<T> const&, shared_ptr<U> const&) const noexcept; 39// template<class T, class U> 40// bool operator()(shared_ptr<T> const&, weak_ptr<U> const&) const noexcept; 41// template<class T, class U> 42// bool operator()(weak_ptr<T> const&, shared_ptr<U> const&) const noexcept; 43// template<class T, class U> 44// bool operator()(weak_ptr<T> const&, weak_ptr<U> const&) const noexcept; 45// 46// typedef unspecified is_transparent; 47// }; 48 49#include <memory> 50#include <cassert> 51#include <set> 52#include "test_macros.h" 53 54struct X {}; 55 56int main() 57{ 58 const std::shared_ptr<int> p1(new int); 59 const std::shared_ptr<int> p2 = p1; 60 const std::shared_ptr<int> p3(new int); 61 const std::weak_ptr<int> w1(p1); 62 const std::weak_ptr<int> w2(p2); 63 const std::weak_ptr<int> w3(p3); 64 65 { 66 typedef std::owner_less<std::shared_ptr<int> > CS; 67 CS cs; 68 69 static_assert((std::is_same<std::shared_ptr<int>, CS::first_argument_type>::value), "" ); 70 static_assert((std::is_same<std::shared_ptr<int>, CS::second_argument_type>::value), "" ); 71 static_assert((std::is_same<bool, CS::result_type>::value), "" ); 72 73 assert(!cs(p1, p2)); 74 assert(!cs(p2, p1)); 75 assert(cs(p1 ,p3) || cs(p3, p1)); 76 assert(cs(p3, p1) == cs(p3, p2)); 77 ASSERT_NOEXCEPT(cs(p1, p1)); 78 79 assert(!cs(p1, w2)); 80 assert(!cs(p2, w1)); 81 assert(cs(p1, w3) || cs(p3, w1)); 82 assert(cs(p3, w1) == cs(p3, w2)); 83 ASSERT_NOEXCEPT(cs(p1, w1)); 84 ASSERT_NOEXCEPT(cs(w1, p1)); 85 } 86 { 87 typedef std::owner_less<std::weak_ptr<int> > CS; 88 CS cs; 89 90 static_assert((std::is_same<std::weak_ptr<int>, CS::first_argument_type>::value), "" ); 91 static_assert((std::is_same<std::weak_ptr<int>, CS::second_argument_type>::value), "" ); 92 static_assert((std::is_same<bool, CS::result_type>::value), "" ); 93 94 assert(!cs(w1, w2)); 95 assert(!cs(w2, w1)); 96 assert(cs(w1, w3) || cs(w3, w1)); 97 assert(cs(w3, w1) == cs(w3, w2)); 98 ASSERT_NOEXCEPT(cs(w1, w1)); 99 100 assert(!cs(w1, p2)); 101 assert(!cs(w2, p1)); 102 assert(cs(w1, p3) || cs(w3, p1)); 103 assert(cs(w3, p1) == cs(w3, p2)); 104 ASSERT_NOEXCEPT(cs(w1, p1)); 105 ASSERT_NOEXCEPT(cs(p1, w1)); 106 } 107#if TEST_STD_VER > 14 108 { 109 std::shared_ptr<int> sp1; 110 std::shared_ptr<void> sp2; 111 std::shared_ptr<long> sp3; 112 std::weak_ptr<int> wp1; 113 114 std::owner_less<> cmp; 115 cmp(sp1, sp2); 116 cmp(sp1, wp1); 117 cmp(sp1, sp3); 118 cmp(wp1, sp1); 119 cmp(wp1, wp1); 120 ASSERT_NOEXCEPT(cmp(sp1, sp1)); 121 ASSERT_NOEXCEPT(cmp(sp1, wp1)); 122 ASSERT_NOEXCEPT(cmp(wp1, sp1)); 123 ASSERT_NOEXCEPT(cmp(wp1, wp1)); 124 } 125 { 126 // test heterogeneous lookups 127 std::set<std::shared_ptr<X>, std::owner_less<>> s; 128 std::shared_ptr<void> vp; 129 s.find(vp); 130 } 131#endif 132} 133