C <math.h> - double_t Type
The C <math.h> double_t type is an alias of one of the fundamental floating-point types at least as wide as double. It is the type used by the implementation to evaluate values of type double, as determined by FLT_EVAL_METHOD.
| FLT_EVAL_METHOD | float_t | double_t |
|---|---|---|
| 0 | float | double |
| 1 | double | double |
| 2 | long double | long double |
| other | implementation-defined | implementation-defined |
In the <math.h> header file, it is defined as follows:
typedef /* implementation-defined */ double_t;
Example:
The example below shows the usage of double_t type.
#include <stdio.h>
#include <math.h>
#include <float.h>
int main (){
printf("FLT_EVAL_METHOD: %d\n", FLT_EVAL_METHOD);
printf("sizeof(float_t): %lu\n", sizeof(float_t));
printf("sizeof(double_t): %lu\n", sizeof(double_t));
printf("sizeof(float): %lu\n", sizeof(float));
printf("sizeof(double): %lu\n", sizeof(double));
printf("sizeof(long double): %lu\n", sizeof(long double));
return 0;
}
The output of the above code will be:
FLT_EVAL_METHOD: 0 sizeof(float_t): 4 sizeof(double_t): 8 sizeof(float): 4 sizeof(double): 8 sizeof(long double): 16
❮ C <math.h> Library
