DESCRIPTION
The header
< 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() |
cacos() |
asin() |
asin() |
casin() |
atan() |
atan() |
catan() |
acosh() |
acosh() |
cacosh() |
asinh() |
asinh() |
casinh() |
atanh() |
atanh() |
catanh() |
cos() |
cos() |
ccos() |
sin() |
sin() |
csin() |
tan() |
tan() |
ctan() |
cosh() |
cosh() |
ccosh() |
sinh() |
sinh() |
csinh() |
tanh() |
tanh() |
ctanh() |
exp() |
exp() |
cexp() |
log() |
log() |
clog() |
pow() |
pow() |
cpow() |
sqrt() |
sqrt() |
csqrt() |
fabs() |
fabs() |
cabs() |
No complex functions exist for the following macros, so passing a complex value to a generic argument invokes undefined behaviour:
atan2() |
fma() |
llround() |
remainder() |
cbrt() |
fmax() |
log10() |
remquo() |
ceil() |
fmin() |
log1p() |
rint() |
copysign() |
fmod() |
log2() |
round() |
erf() |
frexp() |
logb() |
scalbn() |
erfc() |
hypot() |
lrint() |
scalbln() |
exp2() |
ilogb() |
lround() |
tgamma() |
expm1() |
ldexp() |
nextbyint() |
trunc() |
fdim() |
lgamma() |
nextafter() |
|
floor() |
llrint() |
nexttoward() |
|
The following macros always expand to a complex function:
carg() |
cimag() |
conj() |
cproj() |
creal() |
This header includes < complex.h> and < math.h>.
COMPILER SUPPORT
Before ISO/IEC 9899:2011 (“ISO C11”), the header
< tgmath.h> could not be implemented with strictly conforming C code and needed special compiler support. As of ISO/IEC 9899:2011 (“ISO C11”), this header file can be implemented using the
_Generic() language keyword. In addition to compilers that support this keyword, this header file works with GCC.