well a programmer that is coding a linked list in c/c++ probably(definitely) should know the pointer semantics. If they are looking that up then they should be a pass unless you are looking for a really junior programmer. Now if you are asking them to connect to a db and update a record with a stored procedure and they looked up the syntax for a db connection to a mysql database then you know they are fairly proficient at that type of coding but just forgot the exact syntax of a db connection because it's not something done every day whereas any c programmer worth their salt should know basic pointer rules.

Any language I have not used for a while get’s tossed out of the buffer, and I need to lookup even the most basic of syntax when I start coding in it. Once I get going I can easily recall if it’s *, &, ->, or ^ but at the start I really do need a refresher.

PS: Oddly enough, I have little issue working on a multi language programs, it's just I think in terms of pointer not C pointer.