Casting from interface to real class?

[Oliver]

Hi Bill,

Bill Baxter Wrote:

> Bill Baxter wrote:
> > Is it possible to do a dynamic cast from an interface to a real class?
> > 
> > SomeClass k = cast(SomeClass)anInterface;
> > 
> > will that succeed if anInterface started life as a SomeClass?
> 


I hope I understood your question correctly, here is an example.

--------------------
import std.stdio;

interface Expr {
    Expr type();
    void print();
}

Expr steSymbol;

class Symbol : Expr { 
public:
    this(char [] name) { this.itsName = name; }
    char [] getName() { return this.itsName; }
    Expr type() {return steSymbol;}
    void print() {writefln(this.itsName);}
private:
    char [] itsName;    
    int itsInt;
}

int main ( char [][] arg ) { 
    Expr e;
    steSymbol = new Symbol("Symbol");
    e = new Symbol("x");
    steSymbol.print();
    e.print();
    e.type().print();
    Symbol s = cast(Symbol)e;
    s.print();
    writefln((cast(Symbol)e).getName());
    return 0;
}