Number of decimal digits of precision in a double precision floating-point value.
Include
<float.h>
Value
The value 6, by
default; 15 if the switch -fno-short-double is used.
Remarks
By default, a
double type is the same size as a float type
(32-bit representation). The -fno-short-double switch allows the IEEE
64-bit representation to be used for a double precision floating-point value.