id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc 2594,Bug into all_reduce,micdestefano@…,Douglas Gregor,"Good Morning.[[BR]] I've found a bug into the file[[BR]][[BR]] `boost/mpi/collectives/all_reduce.hpp`[[BR]][[BR]] At line 36 you should change[[BR]][[BR]] `is_mpi_op::op()`[[BR]] [[BR]] into[[BR]] [[BR]] `(is_mpi_op::op())`[[BR]] [[BR]] i.e. add a couple of parentheses around the expression. Without those parentheses, this build error occurs:[[BR]] [[BR]] `error: macro ""MPI_Allreduce"" passed 7 arguments, but takes just 6`[[BR]] [[BR]] because the comma that separates template parameters confuses the preprocessor.[[BR]] [[BR]] I've noticed that the bug is still present into the Boost.MPI development version.[[BR]] [[BR]] My compiler is gcc 4.1.2.[[BR]] [[BR]] Thank you in advance.[[BR]] Michele De Stefano",Bugs,closed,Boost 1.39.0,mpi,Boost Development Trunk,Problem,fixed,"all_reduce,",Matthias Troyer