'\" t
.\" Copyright (c) 2020-2022 by Alejandro Colomar <alx@kernel.org>
.\" and Copyright (c) 2020 by Michael Kerrisk <mtk.manpages@gmail.com>
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.TH double_t 3type 2023-10-31 "Linux man-pages 6.7"
.SH NAME
float_t, double_t \- most efficient floating types
.SH LIBRARY
Math library
.RI ( libm )
.SH SYNOPSIS
.nf
.B #include <math.h>
.P
.BR typedef " /* ... */ " float_t;
.BR typedef " /* ... */ " double_t;
.fi
.SH DESCRIPTION
The implementation's most efficient floating types at least as wide as
.I float
and
.I double
respectively.
Their type depends on the value of the macro
.B FLT_EVAL_METHOD
(defined in
.IR <float.h> ):
.P
.TS
lB rI rI.
FLT_EVAL_METHOD	float_t	double_t
.T&
n rI rI.
_
0	float	double
1	double	double
2	long double	long double
.TE
.P
For other values of
.BR FLT_EVAL_METHOD ,
the types of
.I float_t
and
.I double_t
are implementation-defined.
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
C99, POSIX.1-2001.
.SH SEE ALSO
.BR float.h (0p),
.BR math.h (0p)