Update SAFETY documentation

Author: dhardy

src/distr/integer.rs

@@ -119,7 +119,7 @@ impl Distribution<__m128i> for StandardUniform {
         rng.fill_bytes(&mut buf);
         // x86 is little endian so no need for conversion
 
-        // SAFETY: All representations of the source are also representations of the target.
+        // SAFETY: All byte sequences of `buf` represent values of the output type.
         unsafe { core::mem::transmute(buf) }
     }
 }
@@ -132,7 +132,7 @@ impl Distribution<__m256i> for StandardUniform {
         rng.fill_bytes(&mut buf);
         // x86 is little endian so no need for conversion
 
-        // SAFETY: All representations of the source are also representations of the target.
+        // SAFETY: All byte sequences of `buf` represent values of the output type.
         unsafe { core::mem::transmute(buf) }
     }
 }
@@ -148,7 +148,7 @@ impl Distribution<__m512i> for StandardUniform {
         rng.fill_bytes(&mut buf);
         // x86 is little endian so no need for conversion
 
-        // SAFETY: All representations of the source are also representations of the target.
+        // SAFETY: All byte sequences of `buf` represent values of the output type.
         unsafe { core::mem::transmute(buf) }
     }
 }

src/distr/other.rs

@@ -118,7 +118,7 @@ impl Distribution<char> for StandardUniform {
         if n <= 0xDFFF {
             n -= GAP_SIZE;
         }
-        // SAFETY: The representation of `n` is a valid representation of `u32`.
+        // SAFETY: We ensure above that `n` represents a `char`.
         unsafe { char::from_u32_unchecked(n) }
     }
 }

src/rng.rs

@@ -396,7 +396,7 @@ impl Fill for [u8] {
 /// Implement `Fill` for given type `T`.
 ///
 /// # Safety
-/// All representations of `[u8; size_of::<T>()]` are also representations of `T`.
+/// All bit patterns of `[u8; size_of::<T>()]` represent values of `T`.
 macro_rules! unsafe_impl_fill {
     () => {};
     ($t:ty) => {
@@ -405,7 +405,7 @@ macro_rules! unsafe_impl_fill {
                 if self.len() > 0 {
                     let size = mem::size_of_val(self);
                     rng.fill_bytes(
-                        // SAFETY: `self` is not borrowed and all byte sequences are representations of `T`.
+                        // SAFETY: `self` is not borrowed and all byte sequences represent values of `T`.
                         unsafe {
                             slice::from_raw_parts_mut(self.as_mut_ptr()
                                 as *mut u8,
@@ -425,7 +425,7 @@ macro_rules! unsafe_impl_fill {
                 if self.len() > 0 {
                     let size = self.len() * mem::size_of::<$t>();
                     rng.fill_bytes(
-                        // SAFETY: `self` is not borrowed and all byte sequences are representations of `T`.
+                        // SAFETY: `self` is not borrowed and all byte sequences represent values of `T`.
                         unsafe {
                             slice::from_raw_parts_mut(self.as_mut_ptr()
                                 as *mut u8,
@@ -448,9 +448,9 @@ macro_rules! unsafe_impl_fill {
     }
 }
 
-// SAFETY: All representations of `[u8; size_of::<u*>()]` are representations of `u*`.
+// SAFETY: All bit patterns of `[u8; size_of::<T>()]` represent values of `u*`.
 unsafe_impl_fill!(u16, u32, u64, u128,);
-// SAFETY: All representations of `[u8; size_of::<i*>()]` are representations of `i*`.
+// SAFETY: All bit patterns of `[u8; size_of::<T>()]` represent values of `i*`.
 unsafe_impl_fill!(i8, i16, i32, i64, i128,);
 
 impl<T, const N: usize> Fill for [T; N]