swift-mirror/stdlib/stdlib.docc/operator-declarations.md

Operator Declarations

Work with prefix, postfix, and infix operators.

Overview

The tables below list the operators declared by the Swift standard library. For more information about operation declarations, see Operator Declaration in The Swift Programming Language.

The prefix operators are as follows:

Operator	Description
!	Logical NOT
.!	Pointwise logical NOT
~	Bitwise NOT
+	Unary plus
-	Unary minus
..<	Half-open range
...	Closed range

The postfix operators are as follows:

Operator	Description
...	Range

The infix operators are grouped below by precedence group in decreasing order of precedence. If you declare a new operator without specifying a precedence group, it is a member of the DefaultPrecedence precedence group. DefaultPrecedence has no associativity and a precedence immediately higher than TernaryPrecedence.

The BitwiseShiftPrecedence group, which isn’t associative, contains the following infix operators:

Operator	Description
<<	Bitwise left shift
>>	Bitwise right shift
&<<	Bitwise left shift, ignoring overflow
&>>	Bitwise right shift, ignoring overflow

The MultiplicationPrecedence group, which is left associative, contains the following infix operators:

Operator	Description
*	Multiply
/	Divide
%	Remainder
&	Bitwise AND
&*	Multiply with overflow

The AdditionPrecedence group, which is left associative, contains the following infix operators:

Operator	Description
+	Add
-	Subtract
|	Bitwise OR
^	Bitwise XOR
&+	Add with overflow
&-	Subtract with overflow

The RangeFormationPrecedence group, which isn’t associative, contains the following infix operators:

Operator	Description
..<	Half-open range
...	Closed range

The CastingPrecedence group, which is left associative, contains the following infix operators:

Operator	Description
is	Type check
as, as?, and as!	Type cast

The NilCoalescingPrecedence group, which is right associative, contains the following infix operators:

Operator	Description
??	Nil coalescing

The ComparisonPrecedence group, which isn’t associative, contains the following infix operators:

Operator	Description
<	Less than
<=	Less than or equal
>	Greater than
>=	Greater than or equal
==	Equal
!=	Not equal
===	Identical
!==	Not identical
~=	Pattern match
.<	Pointwise less than
.<=	Pointwise less than or equal
.>	Pointwise greater than
.>=	Pointwise greater than or equal
.==	Pointwise equal
.!=	Pointwise not equal

The LogicalConjunctionPrecedence group, which is left associative, contains the following infix operators:

Operator	Description
&&	Logical AND
.&	Pointwise bitwise AND

The LogicalDisjunctionPrecedence group, which is left associative, contains the following infix operators:

Operator	Description
||	Logical OR
.|	Pointwise bitwise OR
.^	Pointwise bitwise XOR

The TernaryPrecedence group, which is right associative, contains the following infix operators:

Operator	Description
? :	Ternary conditional

The AssignmentPrecedence group, which is right associative, contain the following infix operators:

Operator	Description
=	Assign
*=	Multiply and assign
/=	Divide and assign
%=	Remainder and assign
+=	Add and assign
-=	Subtract and assign
<<=	Left bit shift and assign
>>=	Right bit shift and assign
&=	Bitwise AND and assign
|=	Bitwise OR and assign
^=	Bitwise XOR and assign
&*=	Multiply with overflow and assign
&+=	Add with overflow and assign
&-=	Subtract with overflow and assign
&<<=	Left bit shift ignoring overflow and assign
&>>=	Right bit shift ignoring overflow and assign
.&=	Pointwise bitwise AND and assign
.|=	Pointwise bitwise OR and assign
.^=	Pointwise bitwise XOR and assign