26 Numerics library [numerics]

26.5 Bit manipulation [bit]

26.5.6 Rotating [bit.rotate]

In the following descriptions, let N denote numeric_­limits<T>​::​digits.
template<class T> [[nodiscard]] constexpr T rotl(T x, int s) noexcept;
Constraints: T is an unsigned integer type ([basic.fundamental]).
Let r be s % N.
Returns: If r is 0, x; if r is positive, (x << r) | (x >> (N - r)); if r is negative, rotr(x, -r).
template<class T> [[nodiscard]] constexpr T rotr(T x, int s) noexcept;
Constraints: T is an unsigned integer type ([basic.fundamental]).
Let r be s % N.
Returns: If r is 0, x; if r is positive, (x >> r) | (x << (N - r)); if r is negative, rotl(x, -r).