Basically all commonly used languages support this nowadays. Even ones you might not expect like C++ and C# have added it. The only major exceptions that come to mind are C and Java.

You have been able to return a struct by value in C since at least C89:

    typedef struct {
        double d;
        int err;
    } Ret;

    Ret foo(void) {
        Ret r = { 0.0, 43};
        return r;
    }

    int main() {
        Ret r = foo();
    }