This is a great one, and something I wish google had the ability to do:

Search special characters.

This engine, Koders, lets you search various languages and by license type. Want to see an example of how do to something? SImply type in “$hashRef\-\>\{” to see how they do a hashRef in perl.

“To include special search characters, such as ‘*’ as verbatim in your search term, precede the character with a ”, e.g. ‘\*xml*’. Special characters include: + - && || ! ( ) { } [ ] ^ ” ~ * ? : “