Eljay, I actually tried to change the headers, but it did not help (the difference was that compiler did not go through /usr/include/c++/3.2.3/backward/iostream.h:32, but the same error occured again when compiler reached the cctype). Changing extensions does not seem feasible, because I am using FLEX (http://www.gnu.org/software/flex/) - the third party code with many .c files. The key point, I think, is that compiler does not see 'isalnum' etc in cctype. How is it possible? Thanks, Nikolai ----- Original Message ----- From: "Eljay Love-Jensen" <eljay@xxxxxxxxx> To: "Nikolai Nezlobin" <nezlobin@xxxxxxxxxxx>; <gcc-help@xxxxxxxxxxx> Sent: Monday, June 14, 2004 7:44 AM Subject: Re: isalnum not declared | Hi Nikolai, | | It looks like your old source uses old C++ (pre-ISO 14882 standard) header | files. It probably also does not use compliant namespaces. | | Change the header files to compliant ones (e.g., #include <iostream.h> | becomes #include <iostream>). | | And add in std:: by either "std::ID"prefix in front of each standard | namespace identifier (metasyntactically given here as "ID"), or "using | std::ID" near the top of the source file, or just carte blanche by "using | namespace std;" after the #include specifier block near the top of the | source code. | | You might also want to change the ".c" extension to ".cpp". | | HTH, | --Eljay | |