I'm trying to pass 'this' to the constructor using std::make_shared
Example:
// headers
class A
{
public:
std::shared_ptr<B> createB();
}
class B
{
private:
std::shared_ptr<A> a;
public:
B(std::shared_ptr<A>);
}
// source
std::shared_ptr<B> A::createB()
{
auto b = std::make_shared<B>(this); // Compiler error (VS11 Beta)
auto b = std::make_shared<B>(std::shared_ptr<A>(this)); // No compiler error, but doenst work
return b;
}
However this does not work properly, any suggestions how I can properly pass this as an argument?
I think what you probably want here is shared_from_this
.
// headers
class A : std::enable_shared_from_this< A >
{
public:
std::shared_ptr<B> createB();
}
class B
{
private:
std::shared_ptr<A> a;
public:
B(std::shared_ptr<A>);
}
// source
std::shared_ptr<B> A::createB()
{
return std::make_shared<B>( shared_from_this() );
}
Update to include comments from David Rodriguez:
Note that shared_from_this()
should never be called on an object that isn't already managed by a shared_ptr
. This is valid:
shared_ptr<A> a( new A );
a->createB();
While the following leads to undefined behaviour (attempting to call delete
on a
):
A a;
a.createB();