pub unsafe extern "C" fn ALTREP(x: SEXP) -> c_intExpand description
Returns a nonzero value if x is a “compact representation” (ALTREP) value. Access to the data pointers of ALTREP values may be problematic and should be replaced with access to individual elements (see REAL_ELT) or vector subregions (see REAL_GET_REGION). See also: https://svn.r-project.org/R/branches/ALTREP/ALTREP.html