How to use T4 to generate two files at the same time from one template?

Question

I am having a case in which I need to generate two CSharp code files with pretty the same code but different namespace of the input and output types of the methods. In fact each

Answer 1

or you could use the T4 Toolbox (Old CodePlex project, New GitHub project) and use the helpers to generate multiple files.

The author, Oleg Sych, has a documentary blog post (Archived version)

Or if you don't want this dependency just for this functionality, you can use the T4 file MultiOutput.tt (Archived version)