How do I initialise a global array of structs in D?

Question

In aid of my one-man quest to populate SO with D questions (=p), I've run into another problem; initialising an array of structs globally. Observe:

struct A
{
    int a;
    float b;
}

A[2] as;
as[0] = {0, 0.0f};
as[1] = {5, 5.2f};

void main() {}

Results in:

$ dmd wtf.d 
wtf.d(8): no identifier for declarator as[0]
wtf.d(9): no identifier for declarator as[1]

Looking through the docs at Digital Mars, I can't really see anything entirely obvious to me, so I turn once more to the brave denizens of Stack Overflow! I'm guessing the error message doesn't have much to do with the real problem, as surely as[0] is an identifier (but dmd thinks it's a declarator, which AFAICT looking over the docs, it isn't)?

Answer 1

I don't think you can initialise elements on a per-element basis like that. Would this work?

A[2] as = [
    {0, 0.0f},
    {5, 5.2f}
];

Consider what would happen if, in your example, you mentioned as[0] more than once:

as[0] = {0, 0.0f};
as[0] = {1, 1.0f};

What would the value of as[0] be at program initialisation? This is becoming more like statements rather than initialisers.

Note that in D, you can initialise array elements at specific indexes like this:

A[2] as = [
    0: {0, 0.0f},
    1: {5, 5.2f}
];

This would be useful if you have a larger array (such as A[10]) and only need to initialise some of the elements. See Arrays in the D reference documentation for more information.