Array init

[bearophile]

Max Samukha:
> IMO, the initialization code shouldn't be generated for aggregates that have 
> all members void-initialized, and consequently for arrays of such 
> aggregates.

Thanks to all people that have given me answers and opinions.
I have discussed this topic a bit with Tomas Lindquist Olsen, LDC may be improved a bit.


Regarding test code for present and future D1 compilers I written this:

version (Tango)
    import tango.stdc.stdlib: atof;
else
    import std.c.stdlib: atof;

version (V1)
    void main() {
        struct S { double x, y; }
        S s;
        s.x = atof("10.0");
        s.y = atof("20.0");
    }

version (V2)
    void main() {
        struct S { double x, y; }
        S s = void;
        s.x = atof("10.0");
        s.y = atof("20.0");
    }

version (V3)
    void main() {
        struct S { double x, y; }
        auto s = S(atof("10.0"), atof("20.0"));
    }

version (V4)
    void main() {
        struct S { double x = void, y = void; }
        S s;
        s.x = atof("10.0");
        s.y = atof("20.0");
    }

version (V5)
    void main() {
        struct S { double x = void, y = void; }
        S s = void;
        s.x = atof("10.0");
        s.y = atof("20.0");
    }

version (V6)
    void main() {
        struct S { double x = void, y = void; }
        auto s = S(atof("10.0"), atof("20.0"));
    }


I think that in theory a good D compiler has to produce the same optimal code in all those six cases (in some cases removing some double initializations too) :-)
I'll show this code to Lindquist in future.

Bye,
bearophile