add Patterns::is_empty and impl IntoPatterns for Patterns

Author: robjtede

actix-router/CHANGES.md

@@ -7,7 +7,7 @@
 * Fix a bug in multi-patterns where static patterns are interpreted as regex. [#366]
 * Introduce `ResourceDef::pattern_iter` to get an iterator over all patterns in a multi-pattern resource. [#373]
 * Fix segment interpolation leaving `Path` in unintended state after matching. [#368]
-* Fix `ResourceDef` `PartialEq` implementation.
+* Fix `ResourceDef` `PartialEq` implementation. [#373]
 * Re-work `IntoPatterns` trait, adding a `Patterns` enum. [#372]
 * Implement `IntoPatterns` for `bytestring::ByteString`. [#372]
 * Rename `Path::{len => segment_count}` to be more descriptive of it's purpose. [#370]

actix-router/src/lib.rs

@@ -49,6 +49,15 @@ pub enum Patterns {
     List(Vec<String>),
 }
 
+impl Patterns {
+    pub fn is_empty(&self) -> bool {
+        match self {
+            Patterns::Single(_) => false,
+            Patterns::List(pats) => pats.is_empty(),
+        }
+    }
+}
+
 /// Helper trait for type that could be converted to one or more path pattern.
 pub trait IntoPatterns {
     fn patterns(&self) -> Patterns;
@@ -78,6 +87,12 @@ impl IntoPatterns for bytestring::ByteString {
     }
 }
 
+impl IntoPatterns for Patterns {
+    fn patterns(&self) -> Patterns {
+        self.clone()
+    }
+}
+
 impl<T: AsRef<str>> IntoPatterns for Vec<T> {
     fn patterns(&self) -> Patterns {
         let mut patterns = self.iter().map(|v| v.as_ref().to_owned());