Clang++ comand not found

Hi, I tried to install and load dplyr into my R instance, but I got an error having to do with a clang file.

It said --
/bin/sh: x86_64-apple-darwin13.4.0-clang++: command not found
make: *** [RcppExports.o] Error 127
ERROR: compilation failed for package ‘dplyr’

removing ‘/Users/u/anaconda2/lib/R/library/dplyr’
restoring previous ‘/Users/u/anaconda2/lib/R/library/dplyr’
I'm not sure where that command should be or how to get it. Any tips?