[Issue 15246] Destructor inheritance doesn't inherit attributes properly

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15246

--- Comment #6 from Marco Leise <Marco.Leise at gmx.de> ---
I'd agree with you if this was all not observable, but your change causes
friction that I object against. It should be either inheritance all the way or
just sequential calls as right now. Otherwise destructors will be perceived as
inheriting while type-checking and as stand-alone when called directly. To
illustrate this:

    import core.stdc.stdio;
    void main()
    {
        // Get a vanilla 'Ext' object without calling
        // constructors and spoiling the output.
        void[__traits(classInstanceSize, Ext)] buf = void;
        buf[] = typeid(Ext).init[];
        // Show constructor/destructor semantics.
        Ext ext = cast(Ext) buf.ptr;
        ext.__ctor();
        ext.__dtor();
    }
    class Base { 
        void* v;
        this() { printf("Base ctor\n"); }
        ~this() { printf("Base dtor\n"); } // never called
    }
    class Ext : Base { 
        this() { printf("Ext ctor\n"); }
        ~this() @nogc nothrow { printf("Ext dtor\n"); }
    }

Prints:
  Base ctor
  Ext ctor
  Ext dtor

In particular in this example with D's semantics it is correct to have Ext's
destructor be @nogc nothrow while the Base destructor is not. It may be
surprising depending on programming language background, but at least it is
consistently implemented as far as I can tell.

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