11# ` match ` expressions
22
3- > ** <sup >Syntax</sup >**
4- > _ MatchExpression_ :
5- >   ;  ; ` match ` [ _ Expression_ ] <sub >_ except struct expression_ </sub > ` { `
6- >   ;  ;   ;  ; [ _ InnerAttribute_ ] <sup >\* </sup >
7- >   ;  ;   ;  ; _ MatchArms_ <sup >?</sup >
8- >   ;  ; ` } `
9- >
10- > _ MatchArms_ :
11- >   ;  ; ( _ MatchArm_ ` => `
3+ > ** <sup >Syntax</sup >**
4+ > _ MatchExpression_ :
5+ >   ;  ; ` match ` [ _ Expression_ ] <sub >_ except struct expression_ </sub > ` { `
6+ >   ;  ;   ;  ; [ _ InnerAttribute_ ] <sup >\* </sup >
7+ >   ;  ;   ;  ; _ MatchArms_ <sup >?</sup >
8+ >   ;  ; ` } `
9+ >
10+ > _ MatchArms_ :
11+ >   ;  ; ( _ MatchArm_ ` => `
1212> ( [ _ BlockExpression_ ] ` , ` <sup >?</sup >
13- > | [ _ Expression_ ] ` , ` )
14- > )<sup >\* </sup >
15- >   ;  ; _ MatchArm_ ` => ` ( [ _ BlockExpression_ ] | [ _ Expression_ ] ) ` , ` <sup >?</sup >
16- >
17- > _ MatchArm_ :
13+ > | [ _ Expression_ ] ` , ` )
14+ > )<sup >\* </sup >
15+ >   ;  ; _ MatchArm_ ` => ` ( [ _ BlockExpression_ ] | [ _ Expression_ ] ) ` , ` <sup >?</sup >
16+ >
17+ > _ MatchArm_ :
1818>   ;  ; [ _ OuterAttribute_ ] <sup >\* </sup > _ MatchArmPatterns_ _ MatchArmGuard_ <sup >?</sup >
19- >
20- > _ MatchArmPatterns_ :
21- >   ;  ; ` | ` <sup >?</sup > _ Pattern_ ( ` | ` _ Pattern_ )<sup >* </sup >
22- >
23- > _ MatchArmGuard_ :
24- >   ;  ; ` if ` [ _ Expression_ ]
19+ >
20+ > _ MatchArmPatterns_ :
21+ >   ;  ; ` | ` <sup >?</sup > _ Pattern_ ( ` | ` _ Pattern_ )<sup >* </sup >
22+ >
23+ > _ MatchArmGuard_ :
24+ >   ;  ; ` if ` [ _ Expression_ ]
2525
2626A ` match ` expression branches on a * pattern* . The exact form of matching that
2727occurs depends on the pattern. Patterns consist of some combination of
@@ -41,7 +41,7 @@ the pattern are assigned to local variables in the arm's block, and control
4141enters the block.
4242
4343When the head expression is a [ place expression] , the match does not allocate a
44- temporary location; however, a by-value binding may copy or move from the
44+ temporary location; however, a by-value binding may copy or move from the
4545memory location.
4646When possible, it is preferable to match on place expressions, as the lifetime
4747of these matches inherits the lifetime of the place expression rather than being
@@ -118,20 +118,27 @@ match x {
118118}
119119```
120120
121- Multiple match patterns may be joined with the ` | ` operator. A range of values
122- may be specified with ` ... ` . For example:
121+ Multiple match patterns may be joined with the ` | ` operator. An inclusive range
122+ of values may be specified with ` ..= ` . For example:
123123
124124``` rust
125- # let x = 2 ;
125+ # let x = 9 ;
126126let message = match x {
127127 0 | 1 => " not many"
128- 2 ... 9 => " a few"
128+ 2 ..= 9 => " a few"
129129 _ => " lots"
130130};
131+
132+ assert_eq! (message , " a few"
131133```
132134
133- Range patterns only work on [ ` char ` ] and [ numeric types] . A range pattern may
134- not be a sub-range of another range pattern inside the same ` match ` .
135+ Other forms of [ range] \( ` .. ` for an exclusive range, or any range with one or
136+ both endpoints left unspecified) are not supported in matches. The
137+ syntax ` ... ` is also accepted for inclusive ranges in patterns only, for
138+ backwards compatibility.
139+
140+ Range patterns only work [ ` char ` ] and [ numeric types] . A range pattern may not
141+ be a sub-range of another range pattern inside the same ` match ` .
135142
136143Finally, match patterns can accept * pattern guards* to further refine the
137144criteria for matching a case. Pattern guards appear after the pattern and
@@ -157,3 +164,4 @@ let message = match maybe_digit {
157164[ numeric types ] : types.html#numeric-types
158165[ _InnerAttribute_ ] : attributes.html
159166[ _OuterAttribute_ ] : attributes.html
167+ [ range ] : range-expr.html
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