Re: Do we really like the ...It templates?

[mratsim]

@olwi, that creates a closure, if you use that in a loop it will be 
significantly slower than an inline template. See my 
[bench](https://github.com/mratsim/Arraymancer/blob/master/benchmarks/implementation/proc_method_closure_bench.nim)
 in Arraymancer.
    
    
    # Results with -d:release on i5-5257U (dual-core mobile 2.7GHz, turbo 3.1)
    # Proc with ref object 0.099993
    # Closures 2.708598
    # Methods 0.3122219999999998