feature_test_macros is where it's at

I take it this means that erfl() is available if either:
a) the "-std=c99" flag is set; or
b) "_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L" is true.

And, if neither of those 2 conditions is met, then erfl() is unavailable.

Is that the correct way to read it ?

Update: If I #define _BSD_SOURCE at the beginning of LongDouble.xs, does this necessarily mean that erfl() is made available on these problem BSD systems ?

Cheers,
Rob

In reply to Re^2: [C Question] Determine if gcc provides erfl() function by syphilis
in thread [C Question] Determine if gcc provides erfl() function by syphilis

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