NAME
tgmath —
type-generic macros
SYNOPSIS
#include
<tgmath.h>
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() |
nearbyint() |
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>.
STANDARDS
The header
<tgmath.h> conforms to
ISO/IEC 9899:1999
(“ISO C99”).
HISTORY
The header
<tgmath.h> first appeared in
FreeBSD 5.3.
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.
BUGS
Many of the functions mentioned here are not prototyped in
<math.h> or
<complex.h> as they are not
yet implemented. This prevents the corresponding type-generic macro from
working at all.