Update documentation

doc/hash/notes.adoc

@@ -196,8 +196,9 @@ lot of performance on the table, because processing each `char` individually
 is much less efficient than processing several in bulk.
 
 In Boost 1.81, `hash_range` was changed to process elements of type `char`,
-`signed char`, or `unsigned char`, four of a time. A `uint32_t` is composed
-from `first[0]` to `first[3]`, and that `uint32_t` is fed to `hash_combine`.
+`signed char`, `unsigned char`, `std::byte`, or `char8_t`, four of a time.
+A `uint32_t` is composed from `first[0]` to `first[3]`, and that `uint32_t`
+is fed to `hash_combine`.
 
 In principle, when `size_t` is 64 bit, we could have used `uint64_t` instead.
 We do not, because this allows producing an arbitrary hash value by choosing

doc/hash/reference.adoc

@@ -225,7 +225,7 @@ Effects: ::
 +
 --
 When `typename std::iterator_traits<It>::value_type` is not `char`, `signed char`,
-`unsigned char`,
+`unsigned char`, `std::byte`, or `char8_t`,
 
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