I got the following error recently, when I tried to re-compile a program that I've been using for years. error: 'exit' was not declared in this scope So I tried to fix it by changing "exit(0);" to "std:exit(0);" but this did not work: error: 'exit' is not a member of 'std' Then I found that I needed to include a library (that was not necessary before) #include This fixes that problem. Then it told me error: 'strcpy' was not declared in this scope error: 'strcat' was not declared in this scope So I added this line: #include Now it works. -Michael Weeks, July 2014