cxx/test/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.weak.obs/expired.pass.cpp
Howard Hinnant b64f8b07c1 license change
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@119395 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-16 22:09:02 +00:00

47 lines
1008 B
C++

//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <memory>
// weak_ptr
// bool expired() const;
#include <memory>
#include <cassert>
struct A
{
static int count;
A() {++count;}
A(const A&) {++count;}
~A() {--count;}
};
int A::count = 0;
int main()
{
{
std::weak_ptr<A> wp;
assert(wp.use_count() == 0);
assert(wp.expired() == (wp.use_count() == 0));
}
{
std::shared_ptr<A> sp0(new A);
std::weak_ptr<A> wp(sp0);
assert(wp.use_count() == 1);
assert(wp.expired() == (wp.use_count() == 0));
sp0.reset();
assert(wp.use_count() == 0);
assert(wp.expired() == (wp.use_count() == 0));
}
}