-=(_:_:)

Subtracts the second value from the first and stores the difference in the left-hand-side variable.

static func -= (lhs: inout UInt8, rhs: UInt8)

Mangled symbol

ss5UInt8V2seoiyyABz_ABtFZ What are these?

FNV24 hash: 7LSMU

Parameters

lhs: A numeric value.
rhs: The value to subtract from lhs.

The difference of the two arguments must be representable in the arguments’ type. In the following example, the result of 21 - 50 is less than zero, the minimum representable UInt8 value:

var x: UInt8 = 21
x - 50
// Overflow error