Operators and Symbols

Appendix B: Operators and Symbols

This appendix contains a glossary of Rust’s syntax, including operators and other symbols that appear by themselves or in the context of paths, generics, trait bounds, macros, attributes, comments, tuples, and brackets.

Operators

Table B-1 contains the operators in Rust, an example of how the operator would appear in context, a short explanation, and whether that operator is overloadable.

Arithmetic Operators

Operator	Example	Explanation	Overloadable?
+	expr + expr	Arithmetic addition	Add
+=	var += expr	Arithmetic addition and assignment	AddAssign
-	-expr	Arithmetic negation	Neg
-	expr - expr	Arithmetic subtraction	Sub
-=	var -= expr	Arithmetic subtraction and assignment	SubAssign
*	expr * expr	Arithmetic multiplication	Mul
*=	var *= expr	Arithmetic multiplication and assignment	MulAssign
/	expr / expr	Arithmetic division	Div
/=	var /= expr	Arithmetic division and assignment	DivAssign
%	expr % expr	Arithmetic remainder	Rem
%=	var %= expr	Arithmetic remainder and assignment	RemAssign

Comparison Operators

Operator	Example	Explanation	Overloadable?
==	expr == expr	Equality comparison	PartialEq
!=	expr != expr	Nonequality comparison	PartialEq
<	expr < expr	Less than comparison	PartialOrd
<=	expr <= expr	Less than or equal to comparison	PartialOrd
>	expr > expr	Greater than comparison	PartialOrd
>=	expr >= expr	Greater than or equal to comparison	PartialOrd

Logical Operators

Operator	Example	Explanation
!	!expr	Bitwise or logical complement (Not trait)
&&	expr && expr	Short-circuiting logical AND
||	expr || expr	Short-circuiting logical OR

Bitwise Operators

Operator	Example	Explanation	Overloadable?
&	expr & expr	Bitwise AND	BitAnd
&=	var &= expr	Bitwise AND and assignment	BitAndAssign
|	expr | expr	Bitwise OR	BitOr
|=	var |= expr	Bitwise OR and assignment	BitOrAssign
^	expr ^ expr	Bitwise exclusive OR	BitXor
^=	var ^= expr	Bitwise exclusive OR and assignment	BitXorAssign

Reference and Pointer Operators

Operator	Example	Explanation
&	&expr, &mut expr	Borrow
&	&type, &mut type	Borrowed pointer type
*	*expr	Dereference (Deref trait)
*	*const type, *mut type	Raw pointer

Other Operators

Symbol	Explanation
->	Function and closure return type
.	Field access, method call
..	Range (exclusive), struct update syntax
..=	Range (inclusive)
...	Variable-length argument lists
::	Path separator
:	Type annotation, trait bounds
;	Statement terminator
,	Argument and element separator
=>	Match arm syntax
?	Error propagation
@	Pattern binding
_	Ignored pattern binding

Symbols

Brackets and Delimiters

Symbol	Explanation
()	Empty tuple, function calls, grouping
[]	Array/slice indexing, array literals
{}	Block expressions, struct literals

Comments

Symbol	Explanation
//	Line comment
/* */	Block comment
///	Doc comment (outer)
//!	Doc comment (inner)

Attributes

Symbol	Explanation
#[...]	Outer attribute
#![...]	Inner attribute

Macros

Symbol	Explanation
ident!(...)	Macro invocation (parentheses)
ident![...]	Macro invocation (brackets)

Generics and Lifetimes

Symbol	Explanation
<T>	Generic type parameter
<T: Trait>	Generic with trait bound
'a	Lifetime parameter
'static	Static lifetime

For the complete reference, see the official Rust documentation.