c++ - 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 later people didn't care about this issue, or there is some inherent difficulty in implementing designated initializers in the grammar of C++?

Answer 1

I ran into this same problem today. g++ with -std=c++11 and c++14 does support designated initializers, but you can still get a compilation error "test.cxx:78:9: sorry, unimplemented: non-trivial designated initializers not supported" if you don't initialize the struct in the order in which it's members have been defined. As an example

struct x
{
    int a;
    int b;
};

// This is correct
struct x x_1 = {.a = 1, .b = 2};
// This will fail to compile with error non-trivial designated initializer
struct x x_2 = {.b = 1, .a = 2};