ISO_C_BINDING

Standard:

Fortran 2003 and later, GNU extensions

The following intrinsic procedures are provided by the module; their definition can be found in the section Intrinsic Procedures of this manual.

• C_ASSOCIATED

• C_F_POINTER

• C_F_PROCPOINTER

• C_FUNLOCC_LOC

• C_SIZEOF

The ISO_C_BINDING module provides the following named constants of type default integer, which can be used as KIND type parameters.

In addition to the integer named constants required by the Fortran 2003 standard and C_PTRDIFF_T of TS 29113, GNU Fortran provides as an extension named constants for the 128-bit integer types supported by the C compiler: C_INT128_T, C_INT_LEAST128_T, C_INT_FAST128_T. Furthermore, if _Float128 is supported in C, the named constants C_FLOAT128 and C_FLOAT128_COMPLEX are defined.

Fortran Type	Named constant	C type	Extension
INTEGER	C_INT	int
INTEGER	C_SHORT	short int
INTEGER	C_LONG	long int
INTEGER	C_LONG_LONG	long long int
INTEGER	C_SIGNED_CHAR	signed char / unsigned char
INTEGER	C_SIZE_T	size_t
INTEGER	C_INT8_T	int8_t
INTEGER	C_INT16_T	int16_t
INTEGER	C_INT32_T	int32_t
INTEGER	C_INT64_T	int64_t
INTEGER	C_INT128_T	int128_t	Ext.
INTEGER	C_INT_LEAST8_T	int_least8_t
INTEGER	C_INT_LEAST16_T	int_least16_t
INTEGER	C_INT_LEAST32_T	int_least32_t
INTEGER	C_INT_LEAST64_T	int_least64_t
INTEGER	C_INT_LEAST128_T	int_least128_t	Ext.
INTEGER	C_INT_FAST8_T	int_fast8_t
INTEGER	C_INT_FAST16_T	int_fast16_t
INTEGER	C_INT_FAST32_T	int_fast32_t
INTEGER	C_INT_FAST64_T	int_fast64_t
INTEGER	C_INT_FAST128_T	int_fast128_t	Ext.
INTEGER	C_INTMAX_T	intmax_t
INTEGER	C_INTPTR_T	intptr_t
INTEGER	C_PTRDIFF_T	ptrdiff_t	TS 29113
REAL	C_FLOAT	float
REAL	C_DOUBLE	double
REAL	C_LONG_DOUBLE	long double
REAL	C_FLOAT128	_Float128	Ext.
COMPLEX	C_FLOAT_COMPLEX	float _Complex
COMPLEX	C_DOUBLE_COMPLEX	double _Complex
COMPLEX	C_LONG_DOUBLE_COMPLEX	long double _Complex
COMPLEX	C_FLOAT128_COMPLEX	_Float128 _Complex	Ext.
LOGICAL	C_BOOL	_Bool
CHARACTER	C_CHAR	char

Additionally, the following parameters of type CHARACTER(KIND=C_CHAR) are defined.

Name	C definition	Value
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'

Moreover, the following two named constants are defined:

Name	Type
C_NULL_PTR	C_PTR
C_NULL_FUNPTR	C_FUNPTR

Both are equivalent to the value NULL in C.