Re^3: [C Question] Determine if gcc provides erfl() function

The man page for feature_test_macros has lots of details on how to use these, and the info page has even more.

But the easiest way is to set the compiler command line option -std=c99 to ensure that everything (compiler/libc) complies with the C99 standard.

Comment on Re^3: [C Question] Determine if gcc provides erfl() function

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Re^4: [C Question] Determine if gcc provides erfl() function by Anonymous Monk on May 29, 2015 at 20:15 UTC
While those functions are, indeed, a normative part of ISO C99 standard, it unfortunately does not follow that passing an option to gcc might cause a fully compliant environment to magically spring into existence. OP is concerned about BSD systems; a reference to glibc manpages is simply misguided.	[reply]