C# bitwise rotate left and rotate right

Question

What is the C# equivalent (.NET 2.0) of _rotl and _rotr from C++?

Answer 1

Note that if you want to create overloads that operate on shorter integral values, you need to add an extra step, as shown in:

public static byte RotateLeft(
    this byte value,
    int count )
{
    // Unlike the RotateLeft( uint, int ) and RotateLeft( ulong, int ) 
    // overloads, we need to mask out the required bits of count 
    // manually, as the shift operaters will promote a byte to uint, 
    // and will not mask out the correct number of count bits.
    count &= 0x07;
    return (byte)((value << count) | (value >> (8 - count)));
}

The masking operation is not needed for the 32-bit and 64-bit overloads, as the shift operators themselves take care of it for those sizes of left-hand operands.