Update documentation

doc/uuid/changes.adoc

@@ -3,6 +3,12 @@
 
 :idprefix: changes_
 
+== Changes in Boost 1.91.0
+
+* Added `from_chars` to `boost/uuid/uuid_io.hpp`.
+* Added a `noexcept` `operator()` overload to `string_generator`.
+* `string_generator` now supports the Unicode character types in addition to `char` and `wchar_t`.
+
 == Changes in Boost 1.90.0
 
 * `string_generator` is now `constexpr` on {cpp}14 and higher.

doc/uuid/string_generator.adoc

@@ -15,13 +15,17 @@ struct string_generator
     using result_type = uuid;
 
     template<class Ch, class Traits, class Alloc>
-      uuid operator()( std::basic_string<Ch, Traits, Alloc> const& s ) const;
+      constexpr uuid operator()( std::basic_string<Ch, Traits, Alloc> const& s ) const;
 
-    uuid operator()( char const* s ) const;
-    uuid operator()( wchar_t const* s ) const;
+    template<class Ch>
+      constexpr uuid operator()( Ch const* s ) const;
 
     template<class CharIterator>
-      uuid operator()( CharIterator begin, CharIterator end ) const;
+      constexpr uuid operator()( CharIterator first, CharIterator last ) const;
+
+    template<class CharIterator>
+      constexpr uuid operator()( CharIterator first, CharIterator last,
+        int& pos, from_chars_error& err ) const noexcept;
 };
 
 }} // namespace boost::uuids
@@ -52,10 +56,10 @@ Invalid input will generate a `std::runtime_error` exception.
 
 ```
 template<class Ch, class Traits, class Alloc>
-  uuid operator()( std::basic_string<Ch, Traits, Alloc> const& s ) const;
+  constexpr uuid operator()( std::basic_string<Ch, Traits, Alloc> const& s ) const;
 ```
 
-Requires: :: The character type `Ch` of `s` must be either `char` or `wchar_t`.
+Requires: :: The character type `Ch` of `s` must be one of `char`, `wchar_t`, `char8_t`, `char16_t`, `char32_t`.
 
 Effects: :: Parses the string `s` into a `uuid` and returns the result.
 
@@ -71,10 +75,12 @@ uuid u2 = gen( std::wstring( L"01234567-89AB-CDEF-0123-456789ABCDEF" ) );
 ```
 
 ```
-uuid operator()( char const* s ) const;
-uuid operator()( wchar_t const* s ) const;
+template<class Ch>
+  constexpr uuid operator()( Ch const* s ) const;
 ```
 
+Requires: :: `Ch` must be a character type (one of `char`, `wchar_t`, `char8_t`, `char16_t`, `char32_t`).
+
 Effects: :: Parses the string `s` into a `uuid` and returns the result.
 
 Example: ::
@@ -90,12 +96,12 @@ uuid u2 = gen( L"01234567-89ab-cdef-0123-456789abcdef" );
 
 ```
 template<class CharIterator>
-  uuid operator()( CharIterator begin, CharIterator end ) const;
+  constexpr uuid operator()( CharIterator first, CharIterator last ) const;
 ```
 
-Requires: :: `CharIterator` must be an input iterator with a value type of either `char` or `wchar_t`.
+Requires: :: `CharIterator` must be an input iterator with a character value type (one of `char`, `wchar_t`, `char8_t`, `char16_t`, `char32_t`).
 
-Effects: :: Parses the character sequence `[begin, end)` into a `uuid` and returns the result.
+Effects: :: Parses the character sequence `[first, last)` into a `uuid` and returns the result.
 
 Example: ::
 +
@@ -110,3 +116,18 @@ uuid u1 = gen( s1.begin(), s1.end() );
 std::wstring s2( L"01234567-89AB-CDEF-0123-456789ABCDEF" );
 uuid u2 = gen( s2.begin(), s2.end() );
 ```
+
+```
+template<class CharIterator>
+  constexpr uuid operator()( CharIterator first, CharIterator last,
+    int& pos, from_chars_error& err ) const noexcept;
+```
+
+Requires: :: `CharIterator` must be an input iterator with a character value type (one of `char`, `wchar_t`, `char8_t`, `char16_t`, `char32_t`).
+
+Effects: ::
+  Parses the character sequence `[first, last)` into a `uuid` and returns the result.
+  On error, `pos` contains the position at which parsing failed, and `err` contains the error.
+  On success, `err` contains `from_chars_error::none`.
+
+NOTE:  Unlike `from_chars`, this function does not allow extra input; if after a complete UUID is parsed, unconsumed characters remain, `err` is set to `from_chars_error::unexpected_extra_input`.

doc/uuid/uuid_io.adoc

@@ -38,6 +38,29 @@ template<class Ch, std::size_t N>
 std::string to_string( uuid const& u );
 std::wstring to_wstring( uuid const& u );
 
+// from_chars
+
+enum class from_chars_error
+{
+    none = 0,
+
+    unexpected_end_of_input,
+    hex_digit_expected,
+    dash_expected,
+    closing_brace_expected,
+    unexpected_extra_input
+};
+
+template<class Ch> struct from_chars_result
+{
+    Ch const* ptr;
+    from_chars_error ec;
+};
+
+template<class Ch>
+  constexpr from_chars_result<Ch>
+    from_chars( Ch const* first, Ch const* last, uuid& u ) noexcept;
+
 }} // namespace boost::uuids
 ----
 
@@ -209,3 +232,21 @@ std::string s1 = to_string( u );
 
 std::wstring s2 = to_wstring( u );
 ```
+
+=== from_chars
+
+```
+template<class Ch>
+  constexpr from_chars_result<Ch>
+    from_chars( Ch const* first, Ch const* last, uuid& u ) noexcept;
+```
+
+Requires: :: `Ch` must be a character type (one of `char`, `wchar_t`, `char8_t`, `char16_t`, `char32_t`).
+
+Effects: ::
+  Parses a `uuid` string representation from the characters in the range `[first, last)` and stores the result in `u`.
+  On error, the returned `from_chars_result` struct contains the error code in `ec` and `ptr` points to the character at which parsing failed.
+  On success, `ec` contains `from_chars_error::none` and `ptr` points to the character immediately after the last `uuid` character.
+
+NOTE: The values `from_chars_error::closing_brace_expected` and `from_chars_error::unexpected_extra_input` are never returned by `from_chars`.
+  They can be returned from the nonthrowing `string_generator::operator()` overload.