The ISO_C_BINDING named constants represent kind type parameters of data representations compatible with C types.
The following table shows interoperable Fortran types and C Types.
Fortran Type |
Named Constant for the KIND |
C Type |
|---|---|---|
INTEGER |
C_INT |
int |
C_SHORT |
short int |
|
C_LONG |
long int |
|
C_LONG_LONG |
long long int |
|
C_SIGNED_CHAR |
signed char, unsigned char |
|
C_SIZE_T |
size_t |
|
C_INT8_T |
int8_t |
|
C_INT16_T |
int16_t |
|
C_INT32_T |
int32_t |
|
C_INT64_T |
int64_t |
|
C_INT_LEAST8_T |
int_least8_t |
|
C_INT_LEAST16_T |
int_least16_t |
|
C_INT_LEAST32_T |
int_least32_t |
|
C_INT_LEAST64_T |
int_least64_t |
|
C_INT_FAST8_T |
int_fast8_t |
|
C_INT_FAST16_T |
int_fast16_t |
|
C_INT_FAST32_T |
int_fast32_t |
|
C_INT_FAST64_T |
int_fast64_t |
|
C_INTMAX_T |
intmax_t |
|
C_INTPTR_T |
intptr_t |
|
C_PTRDIFF_T |
ptrdiff_t |
|
REAL |
C_FLOAT |
float |
C_DOUBLE |
double |
|
C_LONG_DOUBLE |
long double |
|
COMPLEX |
C_FLOAT_COMPLEX |
float _Complex |
C_DOUBLE_COMPLEX |
double _Complex |
|
C_LONG_DOUBLE_COMPLEX |
long double _Complex |
|
LOGICAL1 |
C_BOOL |
_Bool |
CHARACTER2 |
C_CHAR |
char |
1 Use compiler option fpscomp logicals so that .TRUE. is 1 and .FALSE. is 0 as defined for C's _Bool. 2For character type, the length type parameter must be omitted or it must be specified by a constant expression whose value is one. |
||
For example, an integer type with the kind type parameter C_LONG is interoperable with the C integer type "long" or any C type derived from "long".
The value of C_INT will be a valid value for an integer kind type parameter on the processor. The values for the other integer named constants (C_INT*) will be a valid value for an integer kind type parameter on the processor, if any, or one of the following:
-1 if the C processor defines the corresponding C type and there is no interoperating Fortran processor kind
-2 if the C processor does not define the corresponding C type
The values of C_FLOAT, C_DOUBLE, and C_LONG_DOUBLE will be a valid value for a real kind type parameter on the processor, if any, or one of the following:
-1 if the C processor's type does not have a precision equal to the precision of any of the Fortran processor's real kinds
-2 if the C processor's type does not have a range equal to the range of any of the Fortran processor's real kinds
-3 if the C processor's type has neither the precision or range equal to the precision or range of any of the Fortran processor's real kinds
-4 if there is no interoperating Fortran processor or kind for other reasons
The values of C_FLOAT_COMPLEX, C_DOUBLE_COMPLEX, and C_LONG_DOUBLE_COMPLEX will be the same as those of C_FLOAT, C_DOUBLE, and C_LONG_DOUBLE, respectively.
The value of C_BOOL will be a valid value for a logical kind parameter on the processor, if any, or -1.
The value of C_CHAR is the character kind.
The following table shows interoperable named constants and C characters:
Fortran Named Constant |
Definition |
C Character |
|---|---|---|
C_NULL_CHAR |
null character |
'\0' |
C_ALERT |
alert |
'\a' |
C_BACKSPACE |
backspace |
'\b' |
C_FORM_FEED |
form feed |
'\f' |
C_NEW_LINE |
new line |
'\n' |
C_CARRIAGE_RETURN |
carriage return |
'\r' |
C_HORIZONTAL_TAB |
horizontal tab |
'\t' |
C_VERTICAL_TAB |
vertical tab |
'\v' |
The constant C_NULL_PTR is of type C_PTR; it has the value of a C null data pointer. The constant C_NULL_FUNPTR is of type C_FUNPTR; it has the value of a C null function pointer.