ConfigVersionAndTerm class is added by SERVER-45082(repl_set_config.h). It has two member variables called _version and _term. Both of them are long long type.

long long _version;
long long _term; 

However, the version field is defined as int type in constructor. This is contradictory to definition.

ConfigVersionAndTerm(int version, long long term) : _version(version), _term(term) {} 

Also, in repl_set_config.idl, the version is defined as

ReplSetConfigBase structure. But the max value is defined as 2147483647 which is the 32 bits number's max value.
 
I think the version definition of these places needs to be at least consistent. Or it will lead to ambiguity.