fixed can_transmute/SmallBox::is_inline

src/smallbox.rs

@@ -137,7 +137,8 @@ impl<T> SmallBox<T> {
         // the value can be stored inline iff the size of T is equal or
         // smaller than the size of the boxed type and the alignment of the
         // boxed type is an integer multiple of the alignment of T
-        crate::can_transmute::<Box<MaybeUninit<T>>, T>()
+        (size_of::<Box<MaybeUninit<T>>>() >= size_of::<MaybeUninit<T>>())
+            & (align_of::<Box<MaybeUninit<T>>>() >= align_of::<MaybeUninit<T>>())
     }
 
     pub fn new(value: T) -> Self {

src/util.rs

@@ -44,5 +44,5 @@ pub const fn can_transmute<A, B>() -> bool {
     use core::mem::{align_of, size_of};
     // We can transmute `A` to `B` iff `A` and `B` have the same size and the
     // alignment of `A` is greater than or equal to the alignment of `B`.
-    size_of::<A>() <= size_of::<B>() && align_of::<A>() >= align_of::<B>()
+    (size_of::<A>() == size_of::<B>()) & (align_of::<A>() >= align_of::<B>())
 }