core.simd woes

[F i L]

core.simd vectors are limited in a couple of annoying ways. 
First, if I define:

     @property pure nothrow
     {
         auto x(float4 v) { return v.ptr[0]; }
         auto y(float4 v) { return v.ptr[1]; }
         auto z(float4 v) { return v.ptr[2]; }
         auto w(float4 v) { return v.ptr[3]; }

         void x(ref float4 v, float val) { v.ptr[0] = val; }
         void y(ref float4 v, float val) { v.ptr[1] = val; }
         void z(ref float4 v, float val) { v.ptr[2] = val; }
         void w(ref float4 v, float val) { v.ptr[3] = val; }
     }

Then use it like:

     float4 a, b;

     a.x = a.x + b.x;

it's actually somehow faster than directly using:

     a.ptr[0] += b.ptr[0];

However, notice that I can't use '+=' in the first case, because 
'x' isn't an lvalue. That's really annoying. Moreover, I can't 
assign a vector to anything other than a array of constant 
expressions. Which means I have to make functions just to assign 
vectors in a convenient way.

     float rand = ...;
     float4 vec = [rand, 1, 1, 1]; // ERROR: expected constant


Now, none of this would be an issue at all if I could wrap 
core.simd vectors into custom structs... but doing that complete 
negates their performance gain (I'm guessing because of boxing?). 
It's a different between 2-10x speed improvements using float4 
directly (depending on CPU), and only a few mil secs improvement 
when wrapping float4 in a struct.

So, it's not my ideal situation, but I wouldn't mind at all 
having to use core.simd vector types directly, and moving things 
like dot/cross/normalize/etc to external functions, but if that's 
the case then I would _really_ like some basic usability features 
added to the vector types.

Mono C#'s Mono.Simd.Vector4f, etc, types have these basic 
features, and working with them is much nicer than using D's 
core.simd vectors.