Linux 7 to 9 namespace migration issue
 

I have migrated a large c++ system from linux 7.2 to 9.0 and am getting compile errors on #includes without the .h extension.
Adding the line 'using namespace std;' to each file would be a royal pain. Is there an easier solution?

You can use the old C++ compile that comes in RH . It is g++296. Just use this in the makefile instead of just g++. This solves your problem, atleast temporarily.