stan-dev/stan — pull request #125 by betanalpha (2013-06-18 19:19:57+00:00)
Title: Feature/fast constructor

Speed up NUTS by optimizing copy constructors and assignment operators by avoiding Eigen's (relatively slow) copy constructors. A small overhead is present compared to v1.3.0 which rapidly vanishes for models running more than a few seconds. Further reduction of that overhead would require using pools to avoid temporary allocations.