Logical location of template instantiations

[Steven Schveighoffer via Digitalmars-d]

On 6/27/16 12:25 PM, Lodovico Giaretta wrote:
> import std.conv, core.memory;
>
> struct S
> {
>     int x;
>     private this(int val)
>     {
>         x = val;
>     }
> }
>
> void main()
> {
>     auto ptr = cast(S*)GC.malloc(S.sizeof);
>     auto s = ptr.emplace(3);
> }
>
> This code does not work, as  the call `ptr.emplace(3)` creates a new
> concrete implementation of emplace with parameters `S` and `int`, which
> logically belongs to module std.conv, and so has no access to the
> private constructor.
>
> But, logically speaking, as I'm able to construct objects of S, I should
> also be able to emplace them (which is the same thing, logically) while
> inside my module. What I mean is that in this situation it would be
> better if the call `ptr.emplace(3)` created a new concrete
> implementation of emplace inside the module that called it, to have the
> correct access permissions.

I wonder what the plans are for std.allocator on this, as I would think 
it would run into the same issues. Andrei?

-Steve