double_t
(3type)most efficient floating types
#include <math.h> typedef /* ... */ float_t; typedef /* ... */ double_t;
LIBRARY
DESCRIPTION
The implementation's most efficient floating types at least as wide as float and double respectively. Their type depends on the value of the macro FLT_EVAL_METHOD (defined in <float.h>):
| FLT_EVAL_METHOD | float_t | double_t |
| 0 | float | double |
| 1 | double | double |
| 2 | long double | long double |
For other values of FLT_EVAL_METHOD, the types of float_t and double_t are implementation-defined.