Rcpp?

[mmaechler]

Is it necessary for you to use Rcpp instead of plain C (which is rather faster than slower)?
I'm asking because this will make any back porting to Matrix impossible, AFAICS.

[david-cortes]

Rcpp is not really required, but unfortunately C++ is, since it brings some benefits that do make a difference in timings:

• Hashmaps
• Dynamic vectors
• Faster argsorting
• Faster binary search

Also makes it easier to have functions for different types using templates, compared to putting C functions in headers and playing with macros.

But there's of course workarounds for them, with some penalty in complexity and speed.