Riemann projections

Names specified here
Name	Description				Source
`cproj()`	Compute projection onto Reimann sphere		M	(·)	`<tgmath.h>`	C99	C11
`cproj()`	Compute projection onto Reimann sphere	?		(·)	`<complex.h>`	C99	C11
`cprojf()`	Compute projection onto Reimann sphere	?		(·)	`<complex.h>`	C99	C11
`cprojl()`	Compute projection onto Reimann sphere	?		(·)	`<complex.h>`	C99	C11

#include <complex.h>
float complex cprojf(float complex x);
double complex cproj(double complex x);
long double complex cprojl(long double complex x);

#include <tgmath.h>
complex-type cproj(complex-type x);

The cproj functions compute a projection of the complex number x onto a Riemann sphere. If any part of x is infinite, cproj(x) returns INFINITY + I * copysign(0.0, cimag(x)). Otherwise, it returns x. [Really?] The other functions behave similarly, just with different types.