Let's try this:

    constexpr std::vector<int> f() { return {1,2,3}; }
    constinit std::vector<int> p = f(); // error

in D!

    const(int)[] f() { return [1,2,3]; }
    immutable int[] aaa = f();

And the object file, look ma, aaa[] is statically allocated:

    internal:
        db      001h,000h,000h,000h,002h,000h,000h,000h ;........
        db      003h,000h,000h,000h,000h,000h,000h,000h ;........
    __D5test63aaayAi:
        db      003h,000h,000h,000h,000h,000h,000h,000h ;........
        db      000h,000h,000h,000h,000h,000h,000h,000h ;........