Basic Types

Basic Types — standard GLib types, defined for ease-of-use and portability

Synopsis


#include <glib.h>


typedef             gboolean;
typedef             gpointer;
typedef             gconstpointer;
typedef             gchar;
typedef             guchar;

typedef             gint;
typedef             guint;
typedef             gshort;
typedef             gushort;
typedef             glong;
typedef             gulong;

typedef             gint8;
typedef             guint8;
typedef             gint16;
typedef             guint16;
typedef             gint32;
typedef             guint32;

#define             G_HAVE_GINT64
typedef             gint64;
GLIB_VAR            guint64                             ();
#define             G_GINT64_CONSTANT                   (val)
#define             G_GUINT64_CONSTANT                  (val)

typedef             gfloat;
typedef             gdouble;

typedef             gsize;
typedef             gssize;
typedef             goffset;

Description

GLib defines a number of commonly used types, which can be divided into 4 groups:

New types which are not part of standard C - gboolean, gsize, gssize.
Integer types which are guaranteed to be the same size across all platforms - gint8, guint8, gint16, guint16, gint32, guint32, gint64, guint64.
Types which are easier to use than their standard C counterparts - gpointer, gconstpointer, guchar, guint, gushort, gulong.
Types which correspond exactly to standard C types, but are included for completeness - gchar, gint, gshort, glong, gfloat, gdouble.

Details

gboolean

typedef gint   gboolean;

A standard boolean type. Variables of this type should only contain the value TRUE or FALSE.

gpointer

typedef void* gpointer;

An untyped pointer. gpointer looks better and is easier to use than void*.

gconstpointer

typedef const void *gconstpointer;

An untyped pointer to constant data. The data pointed to should not be changed.

This is typically used in function prototypes to indicate that the data pointed to will not be altered by the function.

gchar

typedef char   gchar;

Corresponds to the standard C char type.

guchar

typedef unsigned char   guchar;

Corresponds to the standard C unsigned char type.

gint

typedef int    gint;

Corresponds to the standard C int type. Values of this type can range from G_MININT to G_MAXINT.

guint

typedef unsigned int    guint;

Corresponds to the standard C unsigned int type. Values of this type can range from 0 to G_MAXUINT.

gshort

typedef short  gshort;

Corresponds to the standard C short type. Values of this type can range from G_MINSHORT to G_MAXSHORT.

gushort

typedef unsigned short  gushort;

Corresponds to the standard C unsigned short type. Values of this type can range from 0 to G_MAXUSHORT.

glong

typedef long   glong;

Corresponds to the standard C long type. Values of this type can range from G_MINLONG to G_MAXLONG.

gulong

typedef unsigned long   gulong;

Corresponds to the standard C unsigned long type. Values of this type can range from 0 to G_MAXULONG.

gint8

typedef signed char gint8;

A signed integer guaranteed to be 8 bits on all platforms. Values of this type can range from -128 to 127.

guint8

typedef unsigned char guint8;

An unsigned integer guaranteed to be 8 bits on all platforms. Values of this type can range from 0 to 255.

gint16

typedef signed short gint16;

A signed integer guaranteed to be 16 bits on all platforms. Values of this type can range from -32,768 to 32,767.

guint16

typedef unsigned short guint16;

An unsigned integer guaranteed to be 16 bits on all platforms. Values of this type can range from 0 to 65,535.

gint32

typedef signed int gint32;

A signed integer guaranteed to be 32 bits on all platforms. Values of this type can range from -2,147,483,648 to 2,147,483,647.

guint32

typedef unsigned int guint32;

An unsigned integer guaranteed to be 32 bits on all platforms. Values of this type can range from 0 to 4,294,967,295.

G_HAVE_GINT64

#define G_HAVE_GINT64 1          /* deprecated, always true */

Warning

G_HAVE_GINT64 is deprecated and should not be used in newly-written code. GLib requires 64-bit integer support since version 2.0, therefore G_HAVE_GINT64 is always defined.

This macro is defined if 64-bit signed and unsigned integers are available on the platform.

gint64

G_GNUC_EXTENSION typedef signed long long gint64;

A signed integer guaranteed to be 64 bits on all platforms. Values of this type can range from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.

guint64 ()

GLIB_VAR            guint64                             ();

An unsigned integer guaranteed to be 64 bits on all platforms. Values of this type can range from 0 to 18,446,744,073,709,551,615.

Returns :

G_GINT64_CONSTANT()

#define G_GINT64_CONSTANT(val)	(G_GNUC_EXTENSION (val##LL))

This macro is used to insert 64-bit integer literals into the source code.

val :

a literal integer value, e.g. 0x1d636b02300a7aa7U.

G_GUINT64_CONSTANT()

#define G_GUINT64_CONSTANT(val)	(G_GNUC_EXTENSION (val##ULL))

This macro is used to insert 64-bit unsigned integer literals into the source code.

val :

a literal integer value, e.g. 0x1d636b02300a7aa7U.

Since 2.10

gfloat

typedef float   gfloat;

Corresponds to the standard C float type. Values of this type can range from -G_MAXFLOAT to G_MAXFLOAT.

gdouble

typedef double  gdouble;

Corresponds to the standard C double type. Values of this type can range from -G_MAXDOUBLE to G_MAXDOUBLE.

gsize

typedef unsigned int gsize;

An unsigned integer type of the result of the sizeof operator, corresponding to the size_t type defined in C99. This type is wide enough to hold the numeric value of a pointer, so it is usually 32bit wide on a 32bit platform and 64bit wide on a 64bit platform.

gssize

typedef signed int gssize;

A signed variant of gsize, corresponding to the ssize_t defined on most platforms.

goffset

typedef gint64 goffset;

A signed integer type that is used for file offsets, corresponding to the C99 type off64_t.

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