std:: rotl

Computes the result of bitwise left-rotating the value of x by s positions. This operation is also known as a left circular shift .

Formally, let N be std:: numeric_limits < T > :: digits and r be s % N .

• If r is ​ 0 ​ , returns x ;
• if r is positive, returns ( x << r ) | ( x >> ( N - r ) ) ;
• if r is negative, returns std:: rotr ( x, - r ) .

This overload participates in overload resolution only if T is an unsigned integer type (that is, unsigned char , unsigned short , unsigned int , unsigned long , unsigned long long , or an extended unsigned integer type).

Parameters

Return value

The result of bitwise left-rotating x by s positions.

Notes

Example

#include <bit>
#include <bitset>
#include <cstdint>
#include <iostream>
 
int main()
{
    using bin = std::bitset<8>;
    const std::uint8_t x{0b00011101};
    std::cout << bin(x) << " <- x\n";
    for (const int s : {0, 1, 4, 9, -1})
        std::cout << bin(std::rotl(x, s)) << " <- rotl(x, " << s << ")\n";
}

00011101 <- x
00011101 <- rotl(x, 0)
00111010 <- rotl(x, 1)
11010001 <- rotl(x, 4)
00111010 <- rotl(x, 9)
10001110 <- rotl(x, -1)

See also