long double complex
foo(long double complex z)
cc -c foo.c
foo.c:7:12: warning: implicitly declaring library function 'cexpl' with type
'_Complex long double (_Complex long double)'
foo.c:7:12: note: include the header <complex.h> or explicitly provide a
declaration for 'cexpl'
1 warning generated.
Isn't cexpl() already mandated by C99? There are also a number of other functions missing from complex.h. See bug #175811.
It looks like Dragonfly-, Net- and OpenBSD already have implementations of cexpl(). Maybe their code could be imported?