42 UOPstream(commsType, toProcNo, buf_, tag, comm,
true, format, version)
OPstream(const commsTypes commsType, const int toProcNo, const label bufSize=0, const int tag=UPstream::msgType(), const label comm=UPstream::worldComm, streamFormat format=BINARY, versionNumber version=currentVersion)
Construct given process index to send to and optional buffer size,.