This release is very large part the work of Thierry Onkelinx who added stable sha1 support in a new function
sha1(). Here, stable means that numerically equivalent numbers (in the sense of the semi-famous R FAQ entry 7.31) result in identical hashes. This is useful for hashing results from numerical analysis---where the representation may differ bitwise between, say, 32 and 64-bit platforms. We started to write a little more about this in a (at this very point still rather unfinished) little vignette.
We also had a nice pull request from fellow Rcpp hacker Qiang Kou who updated the code to use
XLENGTH so that large vectors can be supported.