How to implement a runtime debug assertion without macros in C++ 11/14 with type safety?

An assertion to be used in a context like:

ASSERT(dynamic_cast<Derived*>(_ptr));
ptr = static_cast<Derived*>(ptr);

So during debugging the assertion will check the dynamic cast but will be removed for the release mode. (standard assertion behaviour)

How can I implement this using without macros. What I was thinking was:

void ASSERT(bool _arg)
{
    if(!_arg)
        //something
}

However, this doesn't ensure type safety. Additionally, I was thinking of having two implementations of this, one which is empty(for release, so the ASSERT function does nothing) and another with the code above for debug. This method would also rely on the compiler optimising out the empty function, something which is not always reliable.

Therefore, what would be the best way to go about it? Or are macros absolutely necessary...?