Currently, CCTK_REAL8 are #defines. This is inconvenient, since e.g. CCTK_REAL16 may be "long double", and the C++ syntax
is then illegal, since this expands to "long double(x)". Turning CCTK_REAL8 and friends into proper typedefs remedies this.
The attached patch also corrects two small issues in cctk_Types.h: (1) The include guard around "cctk_Config.h" should not be there, and (2) some #endifs have wrong comments.