Hi all: While reading the IEEE Std 1003.1-2008, i encountered the following paragraph:
"... POSIX.1-2008 defines symbols that are not permitted by other standards to appear in those headers without some control on the visibility of those symbols. Symbols called "feature test macros" are used to control the visibility of symbols that might be included in a header. Implementations, future versions of this standard, and other standards may define additional feature test macros." Does anybody know how 'Feature Test Macros' are implemented ? thanks Saifi.
