How to copy object of class A to another object of class B?

[via Digitalmars-d-learn]

On Wednesday, 28 January 2015 at 09:44:29 UTC, zhmt wrote:
> It is boring coding, I want a solution to copy them 
> automatically:
> void copyObj(SRC,DEST)(SRC src,DEST dest)
> {
> 	foreach (i, type; typeof(SRC.tupleof)) {
> 		auto name = SRC.tupleof[i].stringof;
> 		__traits(getMember, dest, name) =  __traits(getMember, src, 
> name);
> 		writeln(name);
> 	}
> }
>
> Unfortunitely, it doesnt work,  how to improve it?

Haven't tested it, but the `auto name = ...` part is likely to be 
the problem. By using `auto`, your declaring a runtime variable, 
which you then later try to use with `__traits(getMember, ...)`, 
which expects a value known at compile time. Try using `alias 
name = ...`, or if that fails, just repeat the expression 
`SRC.tupleof[i].stringof` wherever `name` occurs (though I'm sure 
there is a nicer way).