Comment by daoxid

> In general, if I need an rvalue and it's legal to convert the lvalue I have into an rvalue, the compiler should do it automatically.

This is already done in some places. Example:

    std::unique_ptr<int> get_int() {
        auto p = std::make_unique<int>(1);

        // `p` is an lvalue but treated as an rvalue in the return statement.
        // (This would not compile otherwise because `p` is not copyable.)
        return p;
    }