Where to put containers of user defined types?
<p>Consider one has some user defined types, and containers of those types that are often manipulated because there are often multiple instances of those types on screen at a time.</p>

<p>Currently I have a header with an associated source file and a namespace to hold these containers, but should I create a separate class to hold them? Should I put the containers in the same header file as the class that they contain (but obviously outside the class)? What is the standard practice for situations like this?</p>
