Am 20.05.2011 19:28, schrieb Michel Fortin:
On 2011-05-20 10:30:33 -0400, Sean Kelly <s...@invisibleduck.org> said:
On May 20, 2011, at 5:14 AM, Benjamin Thaut wrote:
The following program:
import std.stdio;
struct test {
this(this){
writefln("postblit");
}
int foo;
this(int i){
foo = i;
writefln("%x",&foo);
}
~this(){
writefln("%x",&foo);
}
}
void main(string[] args){
test t = test(5);
}
Gives me this output on dmd 2.052:
18fe58
18fe54
Is this a bug in 2.052? (Doesn't happen with 2.053)
Why did the location of the struct change?
Is there any way to get informed about a struct beeing moved?
Is there a way to prevent it?
In main above you're declaring a new struct variable t which is
default-constructed, then a temporary is created and initialized to 5,
and then the temporary is copied onto t. It does seem like a postblit
should probably occur in this scenario though.
Postblit is a post-copy constructor, not a post-move one. There is no
such thing as a post-move constructor in D: structs are assumed to be
movable.
If the compiler was constructing the struct in place (instead of moving
it) it'd be even better, but that's more a question of optimization than
semantics.
What if I need a value type that may be copied, but may not be moved?
--
Kind Regards
Benjamin Thaut
