RAII and classes

[John Colvin via Digitalmars-d-learn]

Potential for leaking references from alias this aside, is there 
some reason that I shouldn't do this for all my C++-like RAII 
needs:

class A
{
        ~this(){ import std.stdio; writeln("hello"); }
}
auto RAII(T)()
if (is(T == class))
{
        struct Inner
        {
                private ubyte[__traits(classInstanceSize, T)] buff;
                T c;
                alias c this;
                
                ~this()
                {
                        destroy(c);
                }
        }
        Inner tmp;
        import std.conv : emplace;
        tmp.c = tmp.buff.emplace!T;
        return tmp;
}

void main()
{
        auto a = RAII!A;
}