The best place for mapping M->VM in MVC?
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I use ASP.NET MVC 3.

I encountered at least 2 approaches for mapping Model->ViewModel on the server side: 

- inside VM class constructor
- inside Controller or designated mapper class

I like first approach the most as the VM property declarations and its mapping are in the same place, easy to maintain and unit-test. Can anybody specify more pros and cons, or other better practice? Thanks