You can annotate D functions as 'pure', which would have that effect, but purity is used for other reasons.

Evaluating functions at compile time has another wrinkle in D - it is path dependent:

    int square(int x) {
        if (x < 100)
            return x * x;
        printf("oops\n");
        return 0;
    }
    const int x = square(3); // works
    const int y = square(100); // fails at compile time

I.e. the path taken through the function has to be pure, not every part of the function.