safety of move
Dmitry Olshansky
dmitry.olsh at gmail.com
Wed Nov 28 07:44:27 PST 2012
11/28/2012 7:19 AM, Ellery Newcomer пишет:
> I find myself using [abusing?] move lately:
>
> import std.algorithm;
> import std.stdio;
>
> struct A {
> const(int) i;
> int j;
> int k;
> }
>
> void main() {
> A* a = new A(); // pretend this is malloc or something
> // *a = A(1)
> A a2 = A(1);
> move(a2, *a);
>
> A[] arr = new A[](2);
> //arr[1] = *a;
> move(*a, arr[1]);
> }
>
> For the first part, I have a A* pointing to uninitialized memory and I
> need to initialize it somehow.
emplace should work for constructing A in a given chunk of memory.
> move works I guess because it uses memcpy
> or something. Not complaining, but wondering.
>
Yes it hacks through const/immutable at ease. The only requirement seems
that it has to be shallow immutable/cont.
> The second part violates D's const semantics and maybe shouldn't be
> permitted. But it is.
I agree.
--
Dmitry Olshansky
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