Is it possible to return an instance of a non-movable, non-copyable type?

Question

In VS2013 update 5, I\'ve got this:

class Lock
{
public:
    Lock(CriticalSection& cs) : cs_(cs)
    {}

    Lock(const Lock&) = delete;
    Lock(Lock&am         


        

Answer 1

If that compiles, it is a bug in the compiler. VC2015 correctly fails to compile it.

class Foo
{
public:
    Foo() {}
    Foo(const Foo&) = delete;
    Foo(Foo&&) = delete;
};


Foo Bar()
{
    return Foo();
}

Gives me:

xxx.cpp(327): error C2280: 'Foo::Foo(Foo &&)': attempting to reference a deleted function

and g++ 4.9 says:

error : use of deleted function 'Foo::Foo(Foo&&)'

The standard is very clear that a copy constructor or move constructor must exist and be accessible, even if RVO means it is not invoked.