Including header file with global variable

问题:

I need to include a header file that contains some global variables (not mine so I cannot change it).

How do I do this so that the variables within the included file are considered 'extern' in all but one case?

回答1:

You cannot. Copy the header and add extern yourself.

回答2:

If the variables are only declared in the header, but aren't assigned a value, then you might be able to do this, depending on the compiler. GCC, for example, has the -fno-common flag to control this behavior.