---
title: "&<<=(_:_:)"
framework: swift
role: symbol
role_heading: Operator
path: "swift/int32/&__=(_:_:)-1642g"
---

# &<<=(_:_:)

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, and stores the result in the left-hand-side variable.

## Declaration

```swift
static func &<<= <Other>(lhs: inout Self, rhs: Other) 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.

## Discussion

Discussion The &<<= operator performs a masking shift, where the value used as rhs is masked to produce a value in the range 0..<lhs.bitWidth. 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. var x: UInt8 = 30                 // 0b00011110 x &<<= 2 // x == 120                       // 0b01111000 However, if you pass 19 as rhs, the method first bitmasks rhs to 3, and then uses that masked value as the number of bits to shift lhs. var y: UInt8 = 30                 // 0b00011110 y &<<= 19 // y == 240                       // 0b11110000