| TGMATH(3) | Library Functions Manual | TGMATH(3) | 
tgmath —
#include <tgmath.h>
<tgmath.h> provides
  type-generic macros for
  <math.h> and
  <complex.h> functions that
  have float (suffixed with f),
  double, and long double (suffixed
  with l) versions. The arguments that vary across the three
  functions and have type float,
  double, and long double,
  respectively, are called generic arguments.
The following rules describe which function is actually called if a type-generic macro is invoked. If any generic argument has type long double or long double complex, the long double function is called. Else, if any generic argument has type double, double complex, or an integer type, the double version is invoked. Otherwise, the macro expands to the float implementation.
For the macros in the following table, both real and complex
    functions exist. The real functions are prototyped in
    <math.h> and the complex
    equivalents in <complex.h>.
    The complex function is called if any of the generic arguments is a complex
    value. Otherwise, the real equivalent is called.
| Macro | Real function | Complex function | 
| acos() | acos(3) | cacos(3) | 
| asin() | asin(3) | casin(3) | 
| atan() | atan(3) | catan(3) | 
| acosh() | acosh(3) | cacosh(3) | 
| asinh() | asinh(3) | casinh(3) | 
| atanh() | atanh(3) | catanh(3) | 
| cos() | cos(3) | ccos(3) | 
| sin() | sin(3) | csin(3) | 
| tan() | tan(3) | ctan(3) | 
| cosh() | cosh(3) | ccosh(3) | 
| sinh() | sinh(3) | csinh(3) | 
| tanh() | tanh(3) | ctanh(3) | 
| exp() | exp(3) | cexp(3) | 
| log() | log(3) | clog(3) | 
| pow() | pow(3) | cpow(3) | 
| sqrt() | sqrt(3) | csqrt(3) | 
| fabs() | fabs(3) | cabs(3) | 
No complex functions exist for the following macros, so passing a complex value to a generic argument invokes undefined behaviour:
| atan2(3) | fma() | llround() | remainder(3) | 
| cbrt(3) | fmax(3) | log10(3) | remquo() | 
| ceil(3) | fmin(3) | log1p(3) | rint(3) | 
| copysign(3) | fmod(3) | log2(3) | round(3) | 
| erf(3) | frexp(3) | logb(3) | scalbn(3) | 
| erfc(3) | hypot(3) | lrint(3) | tgamma() | 
| exp2(3) | ilogb(3) | lround() | trunc(3) | 
| expm1(3) | ldexp(3) | nextafter(3) | |
| fdim(3) | lgamma(3) | ||
| floor(3) | llrint(3) | 
The following macros always expand to a complex function:
| carg(3) | cimag(3) | conj(3) | cproj() | creal(3) | 
<tgmath.h> conforms
  to ISO/IEC 9899:1999 (“ISO C99”).
<tgmath.h> cannot be
  implemented with strictly conforming C code and needs special compiler
  support. The current implementation only works for GCC.
Many of the functions mentioned here are not prototyped in
    <math.h> or
    <complex.h> as they are not
    yet implemented.
| December 14, 2010 | NetBSD 9.3 |