cms-sw/cmssw — pull request #2906 by Dr15Jones (2014-03-17 20:11:01+00:00)
Title: Remove mutables from Propagators

Implementations of the Propagator methods modify member data and therefore these methods can not be ```const```. The decision was if one uses a Propagator one must first ```clone``` the object. This change removes ```const``` from all the actually non-const member functions and then changes all APIs in CMSSW which were using those methods.
This change is necessary for thread-safety.