Simplify internal Allocator trait

Author: Amanieu

src/raw/alloc.rs

@@ -20,18 +20,16 @@ mod inner {
     use crate::alloc::alloc::{alloc, dealloc, Layout};
     use core::ptr::NonNull;
 
-    pub struct AllocError;
-
     pub unsafe trait Allocator {
-        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, AllocError>;
+        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()>;
         unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout);
     }
 
     #[derive(Copy, Clone)]
     pub struct Global;
     unsafe impl Allocator for Global {
-        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, AllocError> {
-            unsafe { NonNull::new(alloc(layout)).ok_or(AllocError) }
+        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> {
+            unsafe { NonNull::new(alloc(layout)).ok_or(()) }
         }
         unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
             dealloc(ptr.as_ptr(), layout)
@@ -45,21 +43,21 @@ mod inner {
 
     #[allow(clippy::map_err_ignore)]
     pub fn do_alloc<A: Allocator>(alloc: &A, layout: Layout) -> Result<NonNull<u8>, ()> {
-        alloc.allocate(layout).map_err(|_| ())
+        alloc.allocate(layout)
     }
 
     #[cfg(feature = "bumpalo")]
     unsafe impl Allocator for bumpalo::Bump {
-        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, AllocError> {
-            self.try_alloc_layout(layout).map_err(|_| AllocError)
+        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> {
+            self.try_alloc_layout(layout).map_err(|_| ())
         }
         unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout) {}
     }
 
     #[cfg(feature = "bumpalo")]
     unsafe impl Allocator for &'_ bumpalo::Bump {
-        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, AllocError> {
-            self.try_alloc_layout(layout).map_err(|_| AllocError)
+        fn allocate(&self, layout: Layout) -> Result<NonNull<u8>, ()> {
+            self.try_alloc_layout(layout).map_err(|_| ())
         }
         unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout) {}
     }