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| -rw-r--r-- | src/doc/tutorial.md | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/doc/tutorial.md b/src/doc/tutorial.md index a7696b45405..75a5840a1ef 100644 --- a/src/doc/tutorial.md +++ b/src/doc/tutorial.md @@ -509,7 +509,7 @@ fn angle(vector: (f64, f64)) -> f64 { let pi = f64::consts::PI; match vector { (0.0, y) if y < 0.0 => 1.5 * pi, - (0.0, y) => 0.5 * pi, + (0.0, _) => 0.5 * pi, (x, y) => atan(y / x) } } @@ -519,7 +519,9 @@ A variable name in a pattern matches any value, *and* binds that name to the value of the matched value inside of the arm's action. Thus, `(0.0, y)` matches any tuple whose first element is zero, and binds `y` to the second element. `(x, y)` matches any two-element tuple, and binds both -elements to variables. +elements to variables. `(0.0,_)` matches any tuple whose first element is zero +and does not bind anything to the second element. + A subpattern can also be bound to a variable, using `variable @ pattern`. For example: |