From: Jonathan Wakely std:: not supportedisspace from <cctype> is a macro
vector::at, deque::at, string::atstd::char_traits<char>::eofstring::clearostream::form and istream::scan
extensions
diff --git a/libstdc++-v3/doc/html/manual/api.html b/libstdc++-v3/doc/html/manual/api.html
index 394c38c3ec5..1849e115936 100644
--- a/libstdc++-v3/doc/html/manual/api.html
+++ b/libstdc++-v3/doc/html/manual/api.html
@@ -405,4 +405,28 @@ now defaults to zero.
for C++20 mode. The removed functionality has been provided by
std::allocator_traits since C++11 and that should
be used instead.
+
+ Experimental C++2a support improved, with new headers
+ <concepts>,
+ <ranges>,
+ <compare>,
+ <coroutine>,
+ <numbers>,
+ <span>,
+ and
+ <stop_token>
+ added.
+
+ The --enable-cheaders=c_std configuration
+ was deprecated.
+
+ When compiling as C++20, the operator>> overloads
+ for extracting strings into character buffers only work with arrays,
+ not raw pointers.
+
+ std::string::reserve(n) will no longer reduce
+ the string's capacity.
+ Calling reserve() with no arguments is equivalent
+ to shrink_to_fit(), but is deprecated.
+ shrink_to_fit() should be used instead.