Auto merge of #3 - thejpster:master, r=japaric

Add modify method to RW.

Cargo.toml

 [package]
-authors = ["Jorge Aparicio <japaricious@gmail.com>"]
+authors = [
+	"Jorge Aparicio <japaricious@gmail.com>",
+	"Jonathan 'theJPster' Pallant <github@thejpster.org.uk>"
+]
 description = "Volatile access to memory mapped hardware registers"
 documentation = "https://docs.rs/volatile-register"
 keywords = ["volatile", "register"]
 license = "MIT OR Apache-2.0"
 name = "volatile-register"
 repository = "https://github.com/japaric/volatile-register"
-version = "0.1.1"
+version = "0.1.2"

src/lib.rs

@@ -78,6 +78,13 @@ impl<T> RW<T>
             ptr::write_volatile(&mut self.register, value);
         }
     }
+
+    /// Perform a read-modify-write, using `func` to perform the modification.
+    pub fn modify<F>(&mut self, func: F) where F: FnOnce(T) -> T {
+        let mut t = self.read();
+        t = func(t);
+        self.write(t);
+    }
 }
 
 /// Write-Only register