Impose structure on array

[Alex]

given some array, is there some way to easily impose structure on 
that array at runtime?

void* data;

auto x = cast(byte[A,B,C])data;

X is then an AxBxC matrix.

I'm having to compute the index myself and it just seems 
unnecessary. A and B are not known at compile time though.

Obviously it should be just as efficient as computing the offset 
manually.

I could probably do this with a struct and override opIndex but 
I'm wondering what is already out there. If it's slower or 
consumes more memory than manual it's not worth it(since my code 
already calcs the index).