Re: std.allocator needs your help

[Jacob Carlborg]

On 2013-09-23 22:32, Timon Gehr wrote:

Some general remarks:
One issue you will probably run into and maybe want to fix in some way
during the typed allocator design is that private constructors cannot be
called from templates parameterized on types.

E.g.:

module a;

auto New(T,Args...)(Args args){
     return new T(args);
}

// ---

module b;

class A{
     private this(){}
}

void main(){
     auto a = New!A(); // error
}

Allocate the memory needed for T without using "new". Then a pointer can 
be used to bypass the protection of the constructor, something like:

extern (C) Object _d_newclass(in ClassInfo);

T New (T, Args ...) (Args args)
{
    auto object = cast(T) _d_newclass(T.classinfo);

    // use explicit type to handle overloads.
    T delegate (Args) dg = &object.__ctor;

    return dg(args);
}

--
/Jacob Carlborg