Improve documentation on match_ref_pats (fixes #532)

README.md

@@ -41,7 +41,7 @@ name
 [linkedlist](https://github.com/Manishearth/rust-clippy/wiki#linkedlist)                                 | warn    | usage of LinkedList, usually a vector is faster, or a more specialized data structure like a VecDeque
 [map_clone](https://github.com/Manishearth/rust-clippy/wiki#map_clone)                                   | warn    | using `.map(|x| x.clone())` to clone an iterator or option's contents (recommends `.cloned()` instead)
 [match_bool](https://github.com/Manishearth/rust-clippy/wiki#match_bool)                                 | warn    | a match on boolean expression; recommends `if..else` block instead
-[match_ref_pats](https://github.com/Manishearth/rust-clippy/wiki#match_ref_pats)                         | warn    | a match has all arms prefixed with `&`; the match expression can be dereferenced instead
+[match_ref_pats](https://github.com/Manishearth/rust-clippy/wiki#match_ref_pats)                         | warn    | a match or `if let` has all arms prefixed with `&`; the match expression can be dereferenced instead
 [min_max](https://github.com/Manishearth/rust-clippy/wiki#min_max)                                       | warn    | `min(_, max(_, _))` (or vice versa) with bounds clamping the result to a constant
 [modulo_one](https://github.com/Manishearth/rust-clippy/wiki#modulo_one)                                 | warn    | taking a number modulo 1, which always returns 0
 [mut_mut](https://github.com/Manishearth/rust-clippy/wiki#mut_mut)                                       | allow   | usage of double-mut refs, e.g. `&mut &mut ...` (either copy'n'paste error, or shows a fundamental misunderstanding of references)

src/matches.rs

@@ -22,7 +22,7 @@ use utils::{snippet, span_lint, span_help_and_lint, in_external_macro, expr_bloc
 declare_lint!(pub SINGLE_MATCH, Warn,
               "a match statement with a single nontrivial arm (i.e, where the other arm \
                is `_ => {}`) is used; recommends `if let` instead");
-/// **What it does:** This lint checks for matches where all arms match a reference, suggesting to remove the reference and deref the matched expression instead. It is `Warn` by default.
+/// **What it does:** This lint checks for matches where all arms match a reference, suggesting to remove the reference and deref the matched expression instead. It also checks for `if let &foo = bar` blocks. It is `Warn` by default.
 ///
 /// **Why is this bad?** It just makes the code less readable. That reference destructuring adds nothing to the code.
 ///
@@ -38,7 +38,7 @@ declare_lint!(pub SINGLE_MATCH, Warn,
 /// }
 /// ```
 declare_lint!(pub MATCH_REF_PATS, Warn,
-              "a match has all arms prefixed with `&`; the match expression can be \
+              "a match or `if let` has all arms prefixed with `&`; the match expression can be \
                dereferenced instead");
 /// **What it does:** This lint checks for matches where match expression is a `bool`. It suggests to replace the expression with an `if...else` block. It is `Warn` by default.
 ///