[util.smartptr.shared.cmp] Add "typename" for dependent name (#1770)

Author: faithandbrave

source/utilities.tex

@@ -9990,9 +9990,9 @@
 \pnum
 \returns
 The first function template returns
-\tcode{less<shared_ptr<T>::element_type*>()(a.get(), nullptr)}.
+\tcode{less<typename shared_ptr<T>::element_type*>()(a.get(), nullptr)}.
 The second function template returns
-\tcode{less<shared_ptr<T>::element_type*>()(nullptr, a.get())}.
+\tcode{less<typename shared_ptr<T>::element_type*>()(nullptr, a.get())}.
 \end{itemdescr}
 
 \indexlibrarymember{operator>}{shared_ptr}%