# Modules and classes

**URL:** <https://www.ruby-forum.com/t/modules-and-classes/91976>\
**Category:** Rails\
**Created:** [April 13, 2007, 10:33pm UTC](https://www.ruby-forum.com/t/modules-and-classes/91976 "2007-04-13T22:33:36Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![simplydope](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/d26b3c/32.png) [@simplydope](https://www.ruby-forum.com/u/simplydope)\
**Post date:** [April 13, 2007, 10:33pm UTC](https://www.ruby-forum.com/t/modules-and-classes/91976/1 "2007-04-13T22:33:36Z")

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I have a module that has a hash of classes and a few methods. For  
example:

SERVICES[Services::ServiceA::SERVICE\_A\_UNIQUE\_ID] = Services::ServiceA  
SERVICES[Services::ServiceB::SERVICE\_B\_UNIQUE\_ID] = Services::ServiceB

This module is then included in various controllers and models where its  
functionality is required.

My question is relating to performance. For every class the module is  
merged into is another class ServiceA, ServiceB created? These are not  
instances so I think not, but just want to check.

Cheers,

George