1. 8.0.1
Type Operator

&<<(_:_:)

Returns the result of shifting a value’s binary representation the specified number of digits to the left, masking the shift amount to the type’s bit width.

• Available because `Self` conforms to `FixedWidthInteger`.

``static func &<< <Other>(lhs: Self, rhs: Other) -> Self where Other : BinaryInteger``

Parameters

lhs

The value to shift.

rhs

The number of bits to shift `lhs` to the left. If `rhs` is outside the range `0..<lhs.bitWidth`, it is masked to produce a value within that range.

Overview

Use the masking left shift operator (`&<<`) when you need to perform a shift and are sure that the shift amount is in the range `0..<lhs.bitWidth`. Before shifting, the masking left shift operator masks the shift to this range. The shift is performed using this masked value.

The following example defines `x` as an instance of `UInt8`, an 8-bit, unsigned integer type. If you use `2` as the right-hand-side value in an operation on `x`, the shift amount requires no masking.

``````let x: UInt8 = 30                 // 0b00011110
let y = x &<< 2
// y == 120                       // 0b01111000``````

However, if you use `8` as the shift amount, the method first masks the shift amount to zero, and then performs the shift, resulting in no change to the original value.

``````let z = x &<< 8
// z == 30                        // 0b00011110``````

If the bit width of the shifted integer type is a power of two, masking is performed using a bitmask; otherwise, masking is performed using a modulo operation.