Why are designated initializers not implemented in g++

Question

Is there any specific reason why has support for designated initializers not been added to g++? Is the reason that C99 standards came late and g++ was developed earlier and

Answer 1

What about anonymous unions?

In C I can have this:

struct vardir_entry {
    const uint16_t id;
    const uint8_t sub;
    const char *name;
    const uint8_t type;

    const union {   
        struct vardir_lookup lookup;
        struct vardir_min_max_conf minmax;       
    };

    const union {
        const struct vardir_value_target_const const_value;
        const struct vardir_value_target value;
    };
};

And initialized like this:

static const struct vardir_entry _directory[]{
        { .id = 0xefef, .sub = 0, .name = "test", .type = VAR_UINT32, .minmax = { .min = 0, .max = 1000 }, .value = VARDIR_ENTRY_VALUE(struct obj, &obj, member) }
    };

However under g++ even with c++14 this gives the same "sorry, unimplemented" error. We do need to be able to define C variables in C++ when we at least want to unit test C code with C++ test framework. The fact that such a valuable feature from C is not being supported is quite a shame.