operator %= { associativity right precedence assignment } Declarations func %= <T where T : _IntegerArithmetic>(_: inout T, rhs: T) Divides lhs and rhs and stores the remainder in lhs, trapping in case of arithmetic overflow (except in -Ounchecked builds). Declaration func %=<T where T : _IntegerArithmetic>(lhs: inout T, rhs: T) func %= <T where T : BinaryInteger>(_: inout T, rhs: T) Declaration func %=<T where T : BinaryInteger>(lhs: inout T, rhs: T)