signed
fn
auto signed(T)(T x) if (isIntegral!T)Returns the corresponding _signed value for x (e.g. if x has type uint, it returns cast(int) x). The advantage compared to the cast is that you do not need to rewrite the cast if x later changes type (e.g from uint to ulong).
Note that the result is always mutable even if the original type was const or immutable. In order to retain the constness, use Signed.