Question

Consider the following code:

static if (!is(MyStruct))
{
    struct MyStruct
    {
    }
}

static if (is(MyStruct))
{
    static assert(0);
}

My original understanding has been that the order of declarations (in global scope) does not matter in D.

However, in this case, the order of the static ifs makes the difference between whether or not the program compiles.

Is D’s compile-time evaluation stage, therefore, a procedural feature (like C/C++), a declarative feature, or something else? What is it currently, and what is it planned to be (if the two are different)?

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Edit:

I just realized, the problem doesn’t even end here. What happens of a static if uses .tupleof to enumerate the members of the current module, and create the same type of problem?

Answer 1

It’s a declarative feature that has procedural properties as a side effect of the implementation.