Adjust to the moving target called the C++ standard. Apparently nowadays it's not allowed to define an explicit copy constructor but not an assignment operator. Consequently, defining the explicit copy constructor in terms of the implicit/automatic assignment operator for general convenience no longer works. Add assignment operators. Caution: not tested with the IBM compiler, but there's no particular reason it shouldn't work.

--- a/oldclasslib/include/strdict.h	Mon May 30 23:32:56 2022 -0400
+++ b/oldclasslib/include/strdict.h	Mon May 30 23:46:22 2022 -0400
@@ -45,8 +45,9 @@
 
   string_dictionary(unsigned size, unsigned word_length = 10);
 
-  string_dictionary(string_dictionary &);
+  string_dictionary(const string_dictionary &);
 
+  void operator = (const string_dictionary &);
 
 // Destructor