Struct d'tors and destructive assignment of return vals

[Steven Schveighoffer]

On Tue, 26 May 2009 21:20:41 -0400, dsimcha <dsimcha at yahoo.com> wrote:

> import std.stdio;
>
> struct RC {
>     uint N;
>
>     this(this) {
>         writeln("Postblit:  ", N);
>     }
>
>     ~this() {
>         writeln("D'tor:  ", N);
>     }
> }
>
> RC fun() {
>     writeln("Doing stuff...");
>     return RC(3);
> }
>
>
> void main() {
>     RC foo = RC(1);
>     writeln("Calling fun()...");
>     foo = fun();
>     writeln("Exiting...");
> }
>
> Output:
>
> Calling fun()...
> Doing stuff...
> D'tor:  1
> Exiting...
> D'tor:  3
>
> Would it be feasible to require that, when a struct is being  
> destructively
> assigned the return value of a function, the d'tor is called for the old
> contents before the function that provides the return value is called  
> instead
> of calling it after?

What if fun throws an exception?

-Steve