rerun benchmarks single threaded

Author: ben-schwen

NEWS.md

@@ -34,18 +34,18 @@
 
     ```R
     x = sample(2e8)
+    setDTthreads(1) # single threaded for fair comparison, will get faster with more threads
     microbenchmark::microbenchmark(
       base = rev(x),
       frev_copy = frev(x, copy=TRUE),
       frev_inplace = frev(x, copy=FALSE),
       times = 10L,
       unit = "s"
     )
-    # Unit: seconds
-    #          expr   min    lq  mean median   uq   max neval cld
-    #          base 1.376 1.397 1.864 1.544 1.917 4.274    10 a  
-    #     frev_copy 0.529 0.591 0.769 0.659 0.727 1.351    10  b 
-    #  frev_inplace 0.064 0.065 0.066 0.066 0.067 0.070    10   c
+    #       expr      min    lq  mean median   uq   max neval cld
+    #       base    1.240 1.263 1.301 1.291 1.329 1.437    10 a  
+    #  frev_copy    0.533 0.538 0.590 0.576 0.639 0.667    10  b 
+    #  frev_inplace 0.099 0.101 0.130 0.102 0.107 0.260    10   c
     ```
 
 ## NOTES

src/utils.c

@@ -425,7 +425,7 @@ SEXP startsWithAny(const SEXP x, const SEXP y, SEXP start) {
 }
 
 SEXP frev(SEXP x, SEXP copyArg) {
-  if (INHERITS(x, char_dataframe) || INHERITS(x, char_datatable))
+  if (INHERITS(x, char_dataframe))
     error(_("'x' should not be data.frame or data.table."));
   if (!isNull(getAttrib(x, R_DimSymbol)))
     error(_("'x' should not be matrix or array"));