Add returning Vec<T> or Vec<some struct> examlpes?

[piaojin]

I have known how to return Vec via example 'vector_return'. But it is hard for me to derive returning Vec or Vec.

[jhg]

@piaojin, I'm not sure what is the example that you want. The vector_return example currently use a Vec, check where it does counted: Vec<_> = and replace _ with the type.