Comment (by Zach Etienne):

I like the idea of testing all the commonly used thorns with single precision, but I worry it’s going to take a long time to debug and fix all the issues. (I’d love to be proven wrong!)

Compiler errors are just the start I fear; consider all the algorithms with tolerances tuned to relative errors ~1e-15 like conservatives-to primitives solvers, AH finders, etc. Also I bet our more complex finite-difference-based and possibly finite-volume-based codes (BSSN & GRMHD codes) will become unstable & unusable. But again, I’d love to be proven wrong.

--
Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2686/rename-cctk_real-double-when-float-is-not