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.\" Copyright (c) 2004 Stefan Farfeleder
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.\" $FreeBSD: src/share/man/man3/tgmath.3,v 1.3 2007/12/15 02:40:10 das Exp $
.\"
.Dd December 14, 2010
.Dt TGMATH 3
.Os
.Sh NAME
.Nm tgmath
.Nd "type-generic macros"
.Sh SYNOPSIS
.In tgmath.h
.Sh DESCRIPTION
The header
.In tgmath.h
provides type-generic macros
for
.In math.h
and
.In complex.h
functions that have
.Vt float
(suffixed with
.Sy f ) ,
.Vt double ,
and
.Vt "long double"
(suffixed with
.Sy l )
versions.
The arguments that vary across the three functions and have type
.Vt float , double ,
and
.Vt "long double" ,
respectively, are called
.Em "generic arguments" .
.Pp
The following rules describe which function is actually called if a
type-generic macro is invoked.
If any generic argument has type
.Vt "long double"
or
.Vt "long double complex" ,
the
.Vt "long double"
function is called.
Else, if any generic argument has type
.Vt double , "double complex" ,
or an integer type, the
.Vt double
version is invoked.
Otherwise, the macro expands to the
.Vt float
implementation.
.Pp
For the macros in the following table, both real and complex functions
exist.
The real functions are prototyped in
.In math.h
and the complex equivalents in
.In complex.h .
The complex function is called if any of the generic arguments is a
complex value.
Otherwise, the real equivalent is called.
.Bl -column -offset indent \
"COMPLEX FUNCTION" "COMPLEX FUNCTION" "COMPLEX FUNCTION"
.It Sy Macro Ta Sy Real function Ta Sy Complex function
.It Fn acos Ta Xr acos 3 Ta Xr cacos 3
.It Fn asin Ta Xr asin 3 Ta Xr casin 3
.It Fn atan Ta Xr atan 3 Ta Xr catan 3
.It Fn acosh Ta Xr acosh 3 Ta Xr cacosh 3
.It Fn asinh Ta Xr asinh 3 Ta Xr casinh 3
.It Fn atanh Ta Xr atanh 3 Ta Xr catanh 3
.It Fn cos Ta Xr cos 3 Ta Xr ccos 3
.It Fn sin Ta Xr sin 3 Ta Xr csin 3
.It Fn tan  Ta Xr tan 3 Ta Xr ctan 3
.It Fn cosh Ta Xr cosh 3 Ta Xr ccosh 3
.It Fn sinh Ta Xr sinh 3 Ta Xr csinh 3
.It Fn tanh Ta Xr tanh 3 Ta Xr ctanh 3
.It Fn exp Ta Xr exp 3 Ta Xr cexp 3
.It Fn log Ta Xr log 3 Ta Xr clog 3
.It Fn pow Ta Xr pow 3 Ta Xr cpow 3
.It Fn sqrt Ta Xr sqrt 3 Ta Xr csqrt 3
.It Fn fabs Ta Xr fabs 3 Ta Xr cabs 3
.El
.Pp
No complex functions exist for the following macros, so passing a
complex value to a generic argument invokes undefined behaviour:
.Bl -column -offset indent ".Fn nexttoward" ".Fn nexttoward" ".Fn nexttoward"
.It Xr atan2 3 Ta Fn fma Ta Fn llround Ta Xr remainder 3
.It Xr cbrt 3 Ta Xr fmax 3 Ta Xr log10 3 Ta Fn remquo
.It Xr ceil 3 Ta Xr fmin 3 Ta Xr log1p 3 Ta Xr rint 3
.It Xr copysign 3 Ta Xr fmod 3 Ta Xr log2 3 Ta Xr round 3
.It Xr erf 3 Ta Xr frexp 3 Ta Xr logb 3 Ta Xr scalbn 3
.It Xr erfc 3 Ta Xr hypot 3 Ta Xr lrint 3 Ta Fn tgamma
.It Xr exp2 3 Ta Xr ilogb 3 Ta Fn lround Ta Xr trunc 3
.It Xr expm1 3 Ta Xr ldexp 3 Ta Xr nextafter 3
.It Xr fdim 3 Ta Xr lgamma 3 Ta
.It Xr floor 3 Ta Xr llrint 3 Ta
.El
.Pp
The following macros always expand to a complex function:
.Bl -column -offset indent ".Fn cimag" ".Fn cimag" ".Fn cimag" ".Fn cimag" ".Fn cimag"
.It Xr carg 3 Ta Xr cimag 3 Ta Xr conj 3 Ta Fn cproj Ta Xr creal 3
.El
.Pp
This header includes
.In complex.h
and
.In math.h .
.Sh STANDARDS
The header
.In tgmath.h
conforms to
.St -isoC-99 .
.Sh AUTHORS
.An Matt Thomas Aq Mt matt@3am-software.com
.Sh BUGS
The header
.In tgmath.h
cannot be implemented with strictly conforming C code and needs
special compiler support.
The current implementation only works for
.Tn GCC .
.Pp
Many of the functions mentioned here are not prototyped in
.In math.h
or
.In complex.h
as they are not yet implemented.