Hello, The GPC runtime library (RTS) does quite a bit of checking at runtime. The ISO standards dictate this. However, these checks slow down GPC compiled programs. Would it be a violation of the standards if we were to have two RTS libraries (libgpc.a and libgpc_g.a), where libgpc_g.a is linked if the '-g' compiler switch is used, and libgpc.a (no checks) otherwise? This would combine the best of both worlds: checks are enabled when you debug your code, while production code has optimum speed. Let me know your opinions, JanJaap --- With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC1925.