core: Don't require copyable options where possible. Closes #2636

Author: brson

src/libcore/option.rs

@@ -87,20 +87,26 @@ pure fn unwrap<T>(-opt: option<T>) -> T unsafe {
     ret liberated_value;
 }
 
-impl extensions<T:copy> for option<T> {
+impl extensions<T> for option<T> {
     #[doc = "
     Update an optional value by optionally running its content through a
     function that returns an option.
     "]
     fn chain<U>(f: fn(T) -> option<U>) -> option<U> { chain(self, f) }
-    #[doc = "Returns the contained value or a default"]
-    fn get_default(def: T) -> T { get_default(self, def) }
     #[doc = "Applies a function to the contained value or returns a default"]
     fn map_default<U: copy>(def: U, f: fn(T) -> U) -> U
         { map_default(self, def, f) }
     #[doc = "Performs an operation on the contained value or does nothing"]
     fn iter(f: fn(T)) { iter(self, f) }
+    #[doc = "Returns true if the option equals `none`"]
+    fn is_none() -> bool { is_none(self) }
+    #[doc = "Returns true if the option contains some value"]
+    fn is_some() -> bool { is_some(self) }
+    #[doc = "Maps a `some` value from one type to another"]
+    fn map<U:copy>(f: fn(T) -> U) -> option<U> { map(self, f) }
+}
 
+impl extensions<T: copy> for option<T> {
     #[doc = "
     Gets the value out of an option
 
@@ -109,12 +115,7 @@ impl extensions<T:copy> for option<T> {
     Fails if the value equals `none`
     "]
     fn get() -> T { get(self) }
-    #[doc = "Returns true if the option equals `none`"]
-    fn is_none() -> bool { is_none(self) }
-    #[doc = "Returns true if the option contains some value"]
-    fn is_some() -> bool { is_some(self) }
-    #[doc = "Maps a `some` value from one type to another"]
-    fn map<U:copy>(f: fn(T) -> U) -> option<U> { map(self, f) }
+    fn get_default(def: T) -> T { get_default(self, def) }
 }
 
 #[test]