Glue code

In software engineering, glue code is code that contributes nothing for the system's goals, serving only to tie loose ends of data structures, like conditions or constraints. It usually happens when an extension (additional feature) is implemented as if on a use case, setting an alternate behaviour to a class by means of a condition, which calls for fragmented code that wasn't originally intended: glue code. This makes original classes harder to understand and their extensions hard to spot at first. Object-oriented development's inability to handle transversal concerns may relate to a lack of more accurate criteria to identify and select the right functional requirements.