array_ref: Evaluate the $offset expr only once in the macro.

root · root · commit 18ae4b236bcd · 2015-09-04T13:51:39.000+02:00
diff --git a/src/lib.rs b/src/lib.rs
@@ -31,7 +31,8 @@ macro_rules! array_ref {
             unsafe fn as_array<T>(slice: &[T]) -> &[T; $len] {
                 &*(slice.as_ptr() as *const [_; $len])
             }
-            let slice = & $arr[$offset..$offset + $len];
+            let offset = $offset;
+            let slice = & $arr[offset..offset + $len];
             unsafe {
                 as_array(slice)
             }
@@ -104,7 +105,8 @@ macro_rules! array_mut_ref {
             unsafe fn as_array<T>(slice: &mut [T]) -> &mut [T; $len] {
                 &mut *(slice.as_mut_ptr() as *mut [_; $len])
             }
-            let slice = &mut $arr[$offset..$offset + $len];
+            let offset = $offset;
+            let slice = &mut $arr[offset..offset + $len];
             unsafe {
                 as_array(slice)
             }

Original file line number	Diff line number	Diff line change
`@@ -31,7 +31,8 @@ macro_rules! array_ref {`
`31`	`31`	`unsafe fn as_array<T>(slice: &[T]) -> &[T; $len] {`
`32`	`32`	`&(slice.as_ptr() as const [_; $len])`
`33`	`33`	`}`
`34`		`- let slice = & $arr[$offset..$offset + $len];`
	`34`	`+ let offset = $offset;`
	`35`	`+ let slice = & $arr[offset..offset + $len];`
`35`	`36`	`unsafe {`
`36`	`37`	`as_array(slice)`
`37`	`38`	`}`
`@@ -104,7 +105,8 @@ macro_rules! array_mut_ref {`
`104`	`105`	`unsafe fn as_array<T>(slice: &mut [T]) -> &mut [T; $len] {`
`105`	`106`	`&mut (slice.as_mut_ptr() as mut [_; $len])`
`106`	`107`	`}`
`107`		`- let slice = &mut $arr[$offset..$offset + $len];`
	`108`	`+ let offset = $offset;`
	`109`	`+ let slice = &mut $arr[offset..offset + $len];`
`108`	`110`	`unsafe {`
`109`	`111`	`as_array(slice)`
`110`	`112`	`}`