Calling copyctor manually

[Paul Backus]

On Saturday, 1 June 2019 at 02:27:36 UTC, SrMordred wrote:
> Its possible to call copyctor manually without calling dtor?
>
> ex, what i did before:
>
> struct T{ ~this(){ writeln("DTOR"); } this(this){ 
> writeln("POSTBLIT"); } }
>
> T a;
> T b;
>
> memcpy(&a,&b,T.sizeof);
> a.__postblit;
>
> /*
> output:
> POSTBLIT
> DTOR
> DTOR
> */
>
> With copy ctors, not sure what to do.
>
>
> struct T{
> ~this(){ writeln("DTOR"); } 	
> this(ref return scope T self){ writeln("COPYCTOR"); } }
>
> T a;
> T b;
>
> memcpy(&a,&b,T.sizeof);
> a.opAssign(b); //???
> //same as a = b;
>
> /*
> output:
> COPYCTOR
> DTOR
> DTOR
> DTOR
> */
>
> I want something like '.__xcopyctor'

The copy constructor is implemented as an overload of `__ctor`:

import std.stdio;

struct T {
     ~this() { writeln("DTOR"); }
     this(ref return scope T self) { writeln("COPYCTOR"); }
}

void main() {
     T a;
     T b;
     a.__ctor(b);
}

/* Output:
COPYCTOR
DTOR
DTOR
*/

https://run.dlang.io/is/NeioBs