string initialization question.

[Steven Schveighoffer]

On Fri, 30 Jul 2010 16:31:49 -0400, Jonathan M Davis  
<jmdavisprog at gmail.com> wrote:

> On Friday, July 30, 2010 13:10:46 Steven Schveighoffer wrote:
>
>> It's not.  The only runtime functions available to the compiler look  
>> like
>> this:
>>
>> _d_newarrayT(TypeInfo ti, size_t length);
>
> I guess that's one thing that comes of not really implementing it as a
> primitive. If there are enough such functions that would be properly  
> optimizable
> had they actually been implemented as primitives, I would think that  
> there would
> be some merit in finding a way to get the compiler to understand that it  
> can do
> such optimizations. But I really don't know how all that works in dmd,  
> so I have
> no idea how feasible that is.

To be clear, the compiler could do the optimization if it had another  
runtime function to call.  But since there is *no* runtime function that  
allocates a new array and initializes it with a custom initial element,  
how do you make a primitive?

So if the function exists, the compiler can be fixed to make the sequence  
of "create then assign" a primitive, but I think just a runtime function  
is good enough, and will work without compiler changes.

-Steve