std::messages_base (3) - Linux Man Pages
Defined in header <locale>
The class std::messages_base provides a type definition which is inherited and used by the std::messages facets.
Member type Definition
catalog /*unspecified signed integer type*/
catalog was erroneously specified as int in C++11, this was corrected in LWG_issue_#2028 and included in C++14
messages (class template)