for C++20 mode. The removed functionality has been provided by
<code class="classname">std::allocator_traits</code> since C++11 and that should
be used instead.
+</p><p>
+ The type of the <code class="classname">std::iterator</code> base class of
+ <code class="classname">std::istreambuf_iterator</code> was changed to be
+ consistent for all <code class="option">-std</code> modes.
+ Before GCC 10.1 the base class had one type in C++98 mode and a
+ different type in C++11 and later modes. The type in C++98 mode
+ was changed to be the same as for C++11 and later.
</p><p>
Experimental C++2a support improved, with new headers
<code class="filename"><concepts></code>,
be used instead.
</para>
+<para>
+ The type of the <classname>std::iterator</classname> base class of
+ <classname>std::istreambuf_iterator</classname> was changed to be
+ consistent for all <option>-std</option> modes.
+ Before GCC 10.1 the base class had one type in C++98 mode and a
+ different type in C++11 and later modes. The type in C++98 mode
+ was changed to be the same as for C++11 and later.
+</para>
+
<para>
Experimental C++2a support improved, with new headers
<filename class="headerfile"><concepts></filename>,