On 06/21/2014 11:56 AM, "Marc Schütz" <schue...@gmx.net>" wrote:
> import std.stdio;
>
> struct A {
> this(this) {
> writeln("A.this(this)");
> }
>
> B b1, b2;
> }
>
> struct B {
> this(this) {
> writeln("B.this(this)");
> }
> }
>
> void main() {
> A a, b;
> a = b;
> }
>
> This outputs:
>
> B.this(this)
> B.this(this)
> A.this(this)
>
> Now, http://dlang.org/struct.html#AssignOverload says:
>
> ref S opAssign(S s)
> {
Note that opAssign takes by-value. The post-blits that you see are due
that copy. i.e. b in main is copied to the argument that opAssign sees.
Also note that if the right-hand side in main() were an rvalue, then
that copy would not involve any post-blit.
> S tmp = this; // bitcopy this into tmp
> this = s; // bitcopy s into this
> tmp.__dtor(); // call destructor on tmp
> return this;
> }
>
> Note the term "bitcopy", which for me implies that no postblits are
> supposed to be called.
>
> What the compiler does makes sense to me, but it seems to contradict the
> documentation. I guess the call to the postblit is missing in the
> pseudo-code... Am I right?
>
> (DMD git 514db2e212ae52e1206d4296e48d4a689370d04b)
Ali
