struct S {

    @disable this(this);

    this(int i) {}

}

​

struct Container(T) {

    T value;

    this(T value) {

        import std.algorithm.mutation : move;

        this.value = move(value);

    }

    import std.traits : isCopyable;

    static if (isCopyable!T) {

        this(ref T value) {

            this.value = value;

        }

    }

}

​

void main()

{

    auto a = Container!S(S(3)); // ok, rvalue is moved

    S s = S(3);

    auto b = Container!S(s); // error, can't copy an S

}