Change the defintion of checked_add! so it can be used in range!

It's tidier that way.

Signed-off-by: mulhern <[email protected]>

src/range_macros.rs

@@ -11,6 +11,8 @@ macro_rules! range {
             pub struct $T(pub u64);
         }
 
+        checked_add!($T);
+
         NewtypeAdd! { () pub struct $T(u64); }
         NewtypeAddAssign! { () pub struct $T(u64); }
         NewtypeDeref! { () pub struct $T(u64); }
@@ -195,9 +197,11 @@ macro_rules! rem {
 
 macro_rules! checked_add {
     ($T: ident) => {
-        /// Add two items of type $T, return None if overflow.
-        pub fn checked_add(&self, other: $T) -> Option<$T> {
-            self.0.checked_add(other.0).map($T)
+        impl $T {
+            /// Add two items of type $T, return None if overflow.
+            pub fn checked_add(&self, other: $T) -> Option<$T> {
+                self.0.checked_add(other.0).map($T)
+            }
         }
-    }
+    };
 }

src/types.rs

@@ -30,10 +30,6 @@ const MAX_META_DEV_SIZE: MetaBlocks = MetaBlocks(255 * ((1 << 14) - 64));
 
 range!(DataBlocks);
 
-impl DataBlocks {
-    checked_add!(DataBlocks);
-}
-
 impl fmt::Display for DataBlocks {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{} data blocks", self.0)
@@ -47,8 +43,6 @@ impl MetaBlocks {
     pub fn sectors(self) -> Sectors {
         self.0 * META_BLOCK_SIZE
     }
-
-    checked_add!(MetaBlocks);
 }
 
 impl fmt::Display for MetaBlocks {
@@ -64,8 +58,6 @@ impl Bytes {
     pub fn sectors(self) -> Sectors {
         Sectors(self.0 / SECTOR_SIZE as u64)
     }
-
-    checked_add!(Bytes);
 }
 
 impl fmt::Display for Bytes {
@@ -86,8 +78,6 @@ impl Sectors {
     pub fn metablocks(self) -> MetaBlocks {
         MetaBlocks(self / META_BLOCK_SIZE)
     }
-
-    checked_add!(Sectors);
 }
 
 impl fmt::Display for Sectors {