C++ Question Initializing a struct.

[Hlynkacg]

In 'C' as well as a few other languages you can fill an array or struct via the following or something similar.

struct foo = {value 1, value 2, value 3, etc...};

however this does not appear to work in C++. Long story short I would like to know why this works.

strobe = new BEACONLIGHTSPEC;
strobe->shape = BEACONSHAPE_STAR;
strobe->pos = &strobe_pos;
strobe->col = &strobe_color;
strobe->size = 0.5;
strobe->falloff = 0.2;
strobe->period = 1.0;
strobe->duration = 0.02;
strobe->tofs = 0.0;
strobe->active = true;

AddBeacon (strobe);

but this does not,

strobe = new BEACONLIGHTSPEC {BEACONSHAPE_STAR, &strobe_pos, &strobe_color, 0.5, 0.2, 1.0, 0.02, 0.0, true};
AddBeacon (strobe);

and if there is a more efficient way to initialize/fill an existing struct than setting the values individually.

note that in both cases "strobe" is a class variable, ie "BEACONLIGHTSPEC *strobe;"

 

[Urwumpe]

Well, you can always use an inline factory method of course in C++ as alternative. Or the constructor for classes.

But the initialization you want to do (automatically assign values to struct during heap memory allocation) does not work in C11 as well.

As quick example from your code:

inline BEACONLIGHTSPEC * NEWBEACONLIGHTSPEC(FOO *strobe_pos, BAR *strobe_color) {
    BEACONLIGHTSPEC *strobe = new BEACONLIGHTSPEC;
    strobe->shape = BEACONSHAPE_STAR;
    strobe->pos = strobe_pos;
    strobe->col = strobe_color;
    strobe->size = 0.5;
    strobe->falloff = 0.2;
    strobe->period = 1.0;
    strobe->duration = 0.02;
    strobe->tofs = 0.0;
    strobe->active = true;

    return strobe;
};

 

[meson800]

strobe = new BEACONLIGHTSPEC {BEACONSHAPE_STAR, &strobe_pos, &strobe_color, 0.5, 0.2, 1.0, 0.02, 0.0, true};
AddBeacon (strobe);

Are you using C++11? That should work...

In pre C++11, afaik you have to do

BEACONLIGHTSPEC temp = { BEACONSHAPE_STAR, &strobe_pos, &strobe_color, 0.5, 0.2, 1.0, 0.02, 0.0, true };
AddBeacon(new BEACONLIGHTSPEC(temp));

Of course, both of those fail if there is a defined constructor/copy assignment/etc instead of the default ones.