api: add From<Match> conversions for Range<usize>

This builds on top of the previous commit which adds a new `range`
method to the `Match` types.

Closes #631

CHANGELOG.md

@@ -2,6 +2,11 @@
 ==================
 This is a small maintenance release with some house cleaning and bug fixes.
 
+New features:
+
+* [FEATURE #631](https://github.com/rust-lang/regex/issues/631):
+  Add a `Match::range` method an a `From<Match> for Range` impl.
+
 Bug fixes:
 
 * [BUG #633](https://github.com/rust-lang/regex/pull/633):

src/re_bytes.rs

@@ -56,6 +56,12 @@ impl<'t> Match<'t> {
     }
 }
 
+impl<'t> From<Match<'t>> for Range<usize> {
+    fn from(m: Match<'t>) -> Range<usize> {
+        m.range()
+    }
+}
+
 /// A compiled regular expression for matching arbitrary bytes.
 ///
 /// It can be used to search, split or replace text. All searching is done with

src/re_unicode.rs

@@ -71,6 +71,12 @@ impl<'t> From<Match<'t>> for &'t str {
     }
 }
 
+impl<'t> From<Match<'t>> for Range<usize> {
+    fn from(m: Match<'t>) -> Range<usize> {
+        m.range()
+    }
+}
+
 /// A compiled regular expression for matching Unicode strings.
 ///
 /// It is represented as either a sequence of bytecode instructions (dynamic)