On 10/24/2014 07:49 AM, Shriramana Sharma via Digitalmars-d-learn wrote:
> the compilers
> are complaining only when I try to assign directly to the member of an
> rvalue, but if I try to assign via a non-const ref returned by a
> non-const method, then it's apparently fine?!! At least shouldn't D
> prohibit this? [Yet another case of rvalue refs being allowed to
> escape?]
>
> nonconst.d:
> --
> struct Pair {
> int x, y ;
> ref Pair handle() { return this ; }
> }
> void main () {
> Pair(1, 2).x = 5 ;
Just to be clear, the above does not compile and the following does compile.
> Pair(1, 2).handle.x = 5 ;
> }
Without flow analysis, it is impossible for the compiler to see that
what handle() returns is an rvalue. Assuming that 'that' is an lvalue,
the following should not be disallowed:
ref Pair handle() {
return isSomeCondition() ? this : that ;
}
Ali
