chore: address MSRV TODOs for 1.81 (#781)

crates/sol-types/src/abi/encoder.rs

@@ -43,6 +43,12 @@ impl Encoder {
         }
     }
 
+    /// Return a reference to the encoded words.
+    #[inline]
+    pub fn words(&self) -> &[Word] {
+        &self.buf
+    }
+
     /// Finish the encoding process, returning the encoded words.
     ///
     /// Use `into_bytes` instead to flatten the words into bytes.
@@ -53,16 +59,18 @@ impl Encoder {
         self.buf
     }
 
+    /// Return a reference to the encoded bytes.
+    #[inline]
+    pub fn bytes(&self) -> &[u8] {
+        // SAFETY: `#[repr(transparent)] FixedBytes<N>([u8; N])`
+        unsafe { &*(self.words() as *const [Word] as *const [[u8; 32]]) }.as_flattened()
+    }
+
     /// Finish the encoding process, returning the encoded bytes.
     #[inline]
     pub fn into_bytes(self) -> Vec<u8> {
-        // TODO: remove once `Vec::into_flattened` is stabilized.
-        // unsafe { mem::transmute::<Vec<_>, Vec<[u8; 32]>>(self.buf) }.into_flattened()
-
         // SAFETY: `#[repr(transparent)] FixedBytes<N>([u8; N])`
-        crate::impl_core::into_flattened::<u8, 32>(unsafe {
-            mem::transmute::<Vec<Word>, Vec<[u8; 32]>>(self.buf)
-        })
+        unsafe { mem::transmute::<Vec<Word>, Vec<[u8; 32]>>(self.finish()) }.into_flattened()
     }
 
     /// Determine the current suffix offset.

crates/sol-types/src/impl_core.rs

@@ -1,16 +1,7 @@
 //! Modified implementations of unstable libcore functions.
 
-use alloc::vec::Vec;
 use core::mem::{self, MaybeUninit};
 
-trait Ext {
-    const IS_ZST: bool;
-}
-
-impl<T> Ext for T {
-    const IS_ZST: bool = mem::size_of::<Self>() == 0;
-}
-
 /// [`core::array::try_from_fn`]
 #[inline]
 pub(crate) fn try_from_fn<F, T, E, const N: usize>(mut cb: F) -> Result<[T; N], E>
@@ -88,34 +79,3 @@ pub(crate) unsafe fn array_assume_init<T, const N: usize>(array: [MaybeUninit<T>
 unsafe fn transpose<T, const N: usize>(array: [MaybeUninit<T>; N]) -> MaybeUninit<[T; N]> {
     mem::transmute_copy::<[MaybeUninit<T>; N], MaybeUninit<[T; N]>>(&mem::ManuallyDrop::new(&array))
 }
-
-// TODO(MSRV-1.80): remove
-/// [`Vec::into_flattened`].
-#[inline]
-pub(crate) fn into_flattened<T, const N: usize>(vec: Vec<[T; N]>) -> Vec<T> {
-    let (ptr, len, cap) = into_raw_parts(vec);
-    let (new_len, new_cap) = if T::IS_ZST {
-        (len.checked_mul(N).expect("vec len overflow"), usize::MAX)
-    } else {
-        // SAFETY:
-        // - `cap * N` cannot overflow because the allocation is already in
-        // the address space.
-        // - Each `[T; N]` has `N` valid elements, so there are `len * N`
-        // valid elements in the allocation.
-        unsafe { (len.checked_mul(N).unwrap_unchecked(), cap.checked_mul(N).unwrap_unchecked()) }
-    };
-    // SAFETY:
-    // - `ptr` was allocated by `self`
-    // - `ptr` is well-aligned because `[T; N]` has the same alignment as `T`.
-    // - `new_cap` refers to the same sized allocation as `cap` because
-    // `new_cap * size_of::<T>()` == `cap * size_of::<[T; N]>()`
-    // - `len` <= `cap`, so `len * N` <= `cap * N`.
-    unsafe { Vec::from_raw_parts(ptr.cast(), new_len, new_cap) }
-}
-
-/// [`Vec::into_raw_parts`]
-#[inline(always)]
-fn into_raw_parts<T>(vec: Vec<T>) -> (*mut T, usize, usize) {
-    let mut me = mem::ManuallyDrop::new(vec);
-    (me.as_mut_ptr(), me.len(), me.capacity())
-}