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glib/glib/docs.c
Philip Withnall 5040de9fc7 docs: Mention gsize, goffset, etc. are in C99 
Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://bugzilla.gnome.org/show_bug.cgi?id=569375
2017-10-06 12:14:59 +01:00

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/*
* Copyright © 2011 Red Hat, Inc
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Matthias Clasen
*/
/* This file collects documentation for macros, typedefs and
* the like, which have no good home in any of the 'real' source
* files.
*/
/* Basic types {{{1 */
/**
* SECTION:types
* @title: Basic Types
* @short_description: standard GLib types, defined for ease-of-use
* and portability
*
* GLib defines a number of commonly used types, which can be divided
* into several groups:
* - New types which are not part of standard C (but are defined in
* various C standard library header files) — #gboolean, #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.
* - Types which correspond exactly to standard C99 types, but are available
* to use even if your compiler does not support C99 — #gsize, #goffset,
* #gintptr, #guintptr.
*
* GLib also defines macros for the limits of some of the standard
* integer and floating point types, as well as macros for suitable
* printf() formats for these types.
*/
/**
* gboolean:
*
* A standard boolean type.
* Variables of this type should only contain the value
* %TRUE or %FALSE.
*/
/**
* gpointer:
*
* An untyped pointer.
* #gpointer looks better and is easier to use than 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:
*
* Corresponds to the standard C char type.
*/
/**
* guchar:
*
* Corresponds to the standard C unsigned char type.
*/
/**
* gint:
*
* Corresponds to the standard C int type.
* Values of this type can range from #G_MININT to #G_MAXINT.
*/
/**
* G_MININT:
*
* The minimum value which can be held in a #gint.
*/
/**
* G_MAXINT:
*
* The maximum value which can be held in a #gint.
*/
/**
* guint:
*
* Corresponds to the standard C unsigned int type.
* Values of this type can range from 0 to #G_MAXUINT.
*/
/**
* G_MAXUINT:
*
* The maximum value which can be held in a #guint.
*/
/**
* gshort:
*
* Corresponds to the standard C short type.
* Values of this type can range from #G_MINSHORT to #G_MAXSHORT.
*/
/**
* G_MINSHORT:
*
* The minimum value which can be held in a #gshort.
*/
/**
* G_MAXSHORT:
*
* The maximum value which can be held in a #gshort.
*/
/**
* gushort:
*
* Corresponds to the standard C unsigned short type.
* Values of this type can range from 0 to #G_MAXUSHORT.
*/
/**
* G_MAXUSHORT:
*
* The maximum value which can be held in a #gushort.
*/
/**
* glong:
*
* Corresponds to the standard C long type.
* Values of this type can range from #G_MINLONG to #G_MAXLONG.
*/
/**
* G_MINLONG:
*
* The minimum value which can be held in a #glong.
*/
/**
* G_MAXLONG:
*
* The maximum value which can be held in a #glong.
*/
/**
* gulong:
*
* Corresponds to the standard C unsigned long type.
* Values of this type can range from 0 to #G_MAXULONG.
*/
/**
* G_MAXULONG:
*
* The maximum value which can be held in a #gulong.
*/
/**
* gint8:
*
* A signed integer guaranteed to be 8 bits on all platforms.
* Values of this type can range from #G_MININT8 (= -128) to
* #G_MAXINT8 (= 127).
*/
/**
* G_MININT8:
*
* The minimum value which can be held in a #gint8.
*
* Since: 2.4
*/
/**
* G_MAXINT8:
*
* The maximum value which can be held in a #gint8.
*
* Since: 2.4
*/
/**
* guint8:
*
* An unsigned integer guaranteed to be 8 bits on all platforms.
* Values of this type can range from 0 to #G_MAXUINT8 (= 255).
*/
/**
* G_MAXUINT8:
*
* The maximum value which can be held in a #guint8.
*
* Since: 2.4
*/
/**
* gint16:
*
* A signed integer guaranteed to be 16 bits on all platforms.
* Values of this type can range from #G_MININT16 (= -32,768) to
* #G_MAXINT16 (= 32,767).
*
* To print or scan values of this type, use
* %G_GINT16_MODIFIER and/or %G_GINT16_FORMAT.
*/
/**
* G_MININT16:
*
* The minimum value which can be held in a #gint16.
*
* Since: 2.4
*/
/**
* G_MAXINT16:
*
* The maximum value which can be held in a #gint16.
*
* Since: 2.4
*/
/**
* G_GINT16_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #gint16 or #guint16. It
* is a string literal, but doesn't include the percent-sign, such
* that you can add precision and length modifiers between percent-sign
* and conversion specifier and append a conversion specifier.
*
* The following example prints "0x7b";
* |[<!-- language="C" -->
* gint16 value = 123;
* g_print ("%#" G_GINT16_MODIFIER "x", value);
* ]|
*
* Since: 2.4
*/
/**
* G_GINT16_FORMAT:
*
* This is the platform dependent conversion specifier for scanning and
* printing values of type #gint16. It is a string literal, but doesn't
* include the percent-sign, such that you can add precision and length
* modifiers between percent-sign and conversion specifier.
*
* |[<!-- language="C" -->
* gint16 in;
* gint32 out;
* sscanf ("42", "%" G_GINT16_FORMAT, &in)
* out = in * 1000;
* g_print ("%" G_GINT32_FORMAT, out);
* ]|
*/
/**
* guint16:
*
* An unsigned integer guaranteed to be 16 bits on all platforms.
* Values of this type can range from 0 to #G_MAXUINT16 (= 65,535).
*
* To print or scan values of this type, use
* %G_GINT16_MODIFIER and/or %G_GUINT16_FORMAT.
*/
/**
* G_MAXUINT16:
*
* The maximum value which can be held in a #guint16.
*
* Since: 2.4
*/
/**
* G_GUINT16_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #guint16. See also #G_GINT16_FORMAT
*/
/**
* gint32:
*
* A signed integer guaranteed to be 32 bits on all platforms.
* Values of this type can range from #G_MININT32 (= -2,147,483,648)
* to #G_MAXINT32 (= 2,147,483,647).
*
* To print or scan values of this type, use
* %G_GINT32_MODIFIER and/or %G_GINT32_FORMAT.
*/
/**
* G_MININT32:
*
* The minimum value which can be held in a #gint32.
*
* Since: 2.4
*/
/**
* G_MAXINT32:
*
* The maximum value which can be held in a #gint32.
*
* Since: 2.4
*/
/**
* G_GINT32_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #gint32 or #guint32. It
* is a string literal. See also #G_GINT16_MODIFIER.
*
* Since: 2.4
*/
/**
* G_GINT32_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #gint32. See also #G_GINT16_FORMAT.
*/
/**
* guint32:
*
* An unsigned integer guaranteed to be 32 bits on all platforms.
* Values of this type can range from 0 to #G_MAXUINT32 (= 4,294,967,295).
*
* To print or scan values of this type, use
* %G_GINT32_MODIFIER and/or %G_GUINT32_FORMAT.
*/
/**
* G_MAXUINT32:
*
* The maximum value which can be held in a #guint32.
*
* Since: 2.4
*/
/**
* G_GUINT32_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #guint32. See also #G_GINT16_FORMAT.
*/
/**
* gint64:
*
* A signed integer guaranteed to be 64 bits on all platforms.
* Values of this type can range from #G_MININT64
* (= -9,223,372,036,854,775,808) to #G_MAXINT64
* (= 9,223,372,036,854,775,807).
*
* To print or scan values of this type, use
* %G_GINT64_MODIFIER and/or %G_GINT64_FORMAT.
*/
/**
* G_MININT64:
*
* The minimum value which can be held in a #gint64.
*/
/**
* G_MAXINT64:
*
* The maximum value which can be held in a #gint64.
*/
/**
* G_GINT64_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #gint64 or #guint64.
* It is a string literal.
*
* Some platforms do not support printing 64-bit integers, even
* though the types are supported. On such platforms %G_GINT64_MODIFIER
* is not defined.
*
* Since: 2.4
*/
/**
* G_GINT64_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #gint64. See also #G_GINT16_FORMAT.
*
* Some platforms do not support scanning and printing 64-bit integers,
* even though the types are supported. On such platforms %G_GINT64_FORMAT
* is not defined. Note that scanf() may not support 64-bit integers, even
* if %G_GINT64_FORMAT is defined. Due to its weak error handling, scanf()
* is not recommended for parsing anyway; consider using g_ascii_strtoull()
* instead.
*/
/**
* guint64:
*
* An unsigned integer guaranteed to be 64-bits on all platforms.
* Values of this type can range from 0 to #G_MAXUINT64
* (= 18,446,744,073,709,551,615).
*
* To print or scan values of this type, use
* %G_GINT64_MODIFIER and/or %G_GUINT64_FORMAT.
*/
/**
* G_MAXUINT64:
*
* The maximum value which can be held in a #guint64.
*/
/**
* G_GUINT64_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #guint64. See also #G_GINT16_FORMAT.
*
* Some platforms do not support scanning and printing 64-bit integers,
* even though the types are supported. On such platforms %G_GUINT64_FORMAT
* is not defined. Note that scanf() may not support 64-bit integers, even
* if %G_GINT64_FORMAT is defined. Due to its weak error handling, scanf()
* is not recommended for parsing anyway; consider using g_ascii_strtoull()
* instead.
*/
/**
* G_GINT64_CONSTANT:
* @val: a literal integer value, e.g. 0x1d636b02300a7aa7
*
* This macro is used to insert 64-bit integer literals
* into the source code.
*/
/**
* G_GUINT64_CONSTANT:
* @val: a literal integer value, e.g. 0x1d636b02300a7aa7U
*
* This macro is used to insert 64-bit unsigned integer
* literals into the source code.
*
* Since: 2.10
*/
/**
* gfloat:
*
* Corresponds to the standard C float type.
* Values of this type can range from -#G_MAXFLOAT to #G_MAXFLOAT.
*/
/**
* G_MINFLOAT:
*
* The minimum positive value which can be held in a #gfloat.
*
* If you are interested in the smallest value which can be held
* in a #gfloat, use -%G_MAXFLOAT.
*/
/**
* G_MAXFLOAT:
*
* The maximum value which can be held in a #gfloat.
*/
/**
* gdouble:
*
* Corresponds to the standard C double type.
* Values of this type can range from -#G_MAXDOUBLE to #G_MAXDOUBLE.
*/
/**
* G_MINDOUBLE:
*
* The minimum positive value which can be held in a #gdouble.
*
* If you are interested in the smallest value which can be held
* in a #gdouble, use -%G_MAXDOUBLE.
*/
/**
* G_MAXDOUBLE:
*
* The maximum value which can be held in a #gdouble.
*/
/**
* 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 32 bit wide on a 32-bit platform and 64 bit wide
* on a 64-bit platform. Values of this type can range from 0 to
* #G_MAXSIZE.
*
* To print or scan values of this type, use
* %G_GSIZE_MODIFIER and/or %G_GSIZE_FORMAT.
*/
/**
* G_MAXSIZE:
*
* The maximum value which can be held in a #gsize.
*
* Since: 2.4
*/
/**
* G_GSIZE_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #gsize. It
* is a string literal.
*
* Since: 2.6
*/
/**
* G_GSIZE_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #gsize. See also #G_GINT16_FORMAT.
*
* Since: 2.6
*/
/**
* gssize:
*
* A signed variant of #gsize, corresponding to the
* ssize_t defined on most platforms.
* Values of this type can range from #G_MINSSIZE
* to #G_MAXSSIZE.
*
* To print or scan values of this type, use
* %G_GSSIZE_MODIFIER and/or %G_GSSIZE_FORMAT.
*/
/**
* G_MINSSIZE:
*
* The minimum value which can be held in a #gssize.
*
* Since: 2.14
*/
/**
* G_MAXSSIZE:
*
* The maximum value which can be held in a #gssize.
*
* Since: 2.14
*/
/**
* G_GSSIZE_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #gssize. See also #G_GINT16_FORMAT.
*
* Since: 2.6
*/
/**
* G_GSSIZE_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #gssize. It
* is a string literal.
*
* Since: 2.6
*/
/**
* goffset:
*
* A signed integer type that is used for file offsets,
* corresponding to the C99 type off64_t.
* Values of this type can range from #G_MINOFFSET to
* #G_MAXOFFSET.
*
* To print or scan values of this type, use
* %G_GOFFSET_MODIFIER and/or %G_GOFFSET_FORMAT.
*
* Since: 2.14
*/
/**
* G_MINOFFSET:
*
* The minimum value which can be held in a #goffset.
*/
/**
* G_MAXOFFSET:
*
* The maximum value which can be held in a #goffset.
*/
/**
* G_GOFFSET_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #goffset. It is a string
* literal. See also #G_GINT64_MODIFIER.
*
* Since: 2.20
*/
/**
* G_GOFFSET_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #goffset. See also #G_GINT64_FORMAT.
*
* Since: 2.20
*/
/**
* G_GOFFSET_CONSTANT:
* @val: a literal integer value, e.g. 0x1d636b02300a7aa7
*
* This macro is used to insert #goffset 64-bit integer literals
* into the source code.
*
* See also #G_GINT64_CONSTANT.
*
* Since: 2.20
*/
/**
* gintptr:
*
* Corresponds to the C99 type intptr_t,
* a signed integer type that can hold any pointer.
*
* To print or scan values of this type, use
* %G_GINTPTR_MODIFIER and/or %G_GINTPTR_FORMAT.
*
* Since: 2.18
*/
/**
* G_GINTPTR_MODIFIER:
*
* The platform dependent length modifier for conversion specifiers
* for scanning and printing values of type #gintptr or #guintptr.
* It is a string literal.
*
* Since: 2.22
*/
/**
* G_GINTPTR_FORMAT:
*
* This is the platform dependent conversion specifier for scanning
* and printing values of type #gintptr.
*
* Since: 2.22
*/
/**
* guintptr:
*
* Corresponds to the C99 type uintptr_t,
* an unsigned integer type that can hold any pointer.
*
* To print or scan values of this type, use
* %G_GINTPTR_MODIFIER and/or %G_GUINTPTR_FORMAT.
*
* Since: 2.18
*/
/**
* G_GUINTPTR_FORMAT:
*
* This is the platform dependent conversion specifier
* for scanning and printing values of type #guintptr.
*
* Since: 2.22
*/
/* Type conversion {{{1 */
/**
* SECTION:type_conversion
* @title: Type Conversion Macros
* @short_description: portably storing integers in pointer variables
*
* Many times GLib, GTK+, and other libraries allow you to pass "user
* data" to a callback, in the form of a void pointer. From time to time
* you want to pass an integer instead of a pointer. You could allocate
* an integer, with something like:
* |[<!-- language="C" -->
* int *ip = g_new (int, 1);
* *ip = 42;
* ]|
* But this is inconvenient, and it's annoying to have to free the
* memory at some later time.
*
* Pointers are always at least 32 bits in size (on all platforms GLib
* intends to support). Thus you can store at least 32-bit integer values
* in a pointer value. Naively, you might try this, but it's incorrect:
* |[<!-- language="C" -->
* gpointer p;
* int i;
* p = (void*) 42;
* i = (int) p;
* ]|
* Again, that example was not correct, don't copy it.
* The problem is that on some systems you need to do this:
* |[<!-- language="C" -->
* gpointer p;
* int i;
* p = (void*) (long) 42;
* i = (int) (long) p;
* ]|
* The GLib macros GPOINTER_TO_INT(), GINT_TO_POINTER(), etc. take care
* to do the right thing on the every platform.
*
* Warning: You may not store pointers in integers. This is not
* portable in any way, shape or form. These macros only allow storing
* integers in pointers, and only preserve 32 bits of the integer; values
* outside the range of a 32-bit integer will be mangled.
*/
/**
* GINT_TO_POINTER:
* @i: integer to stuff into a pointer
*
* Stuffs an integer into a pointer type.
*
* Remember, you may not store pointers in integers. This is not portable
* in any way, shape or form. These macros only allow storing integers in
* pointers, and only preserve 32 bits of the integer; values outside the
* range of a 32-bit integer will be mangled.
*/
/**
* GPOINTER_TO_INT:
* @p: pointer containing an integer
*
* Extracts an integer from a pointer. The integer must have
* been stored in the pointer with GINT_TO_POINTER().
*
* Remember, you may not store pointers in integers. This is not portable
* in any way, shape or form. These macros only allow storing integers in
* pointers, and only preserve 32 bits of the integer; values outside the
* range of a 32-bit integer will be mangled.
*/
/**
* GUINT_TO_POINTER:
* @u: unsigned integer to stuff into the pointer
*
* Stuffs an unsigned integer into a pointer type.
*/
/**
* GPOINTER_TO_UINT:
* @p: pointer to extract an unsigned integer from
*
* Extracts an unsigned integer from a pointer. The integer must have
* been stored in the pointer with GUINT_TO_POINTER().
*/
/**
* GSIZE_TO_POINTER:
* @s: #gsize to stuff into the pointer
*
* Stuffs a #gsize into a pointer type.
*/
/**
* GPOINTER_TO_SIZE:
* @p: pointer to extract a #gsize from
*
* Extracts a #gsize from a pointer. The #gsize must have
* been stored in the pointer with GSIZE_TO_POINTER().
*/
/* Byte order {{{1 */
/**
* SECTION:byte_order
* @title: Byte Order Macros
* @short_description: a portable way to convert between different byte orders
*
* These macros provide a portable way to determine the host byte order
* and to convert values between different byte orders.
*
* The byte order is the order in which bytes are stored to create larger
* data types such as the #gint and #glong values.
* The host byte order is the byte order used on the current machine.
*
* Some processors store the most significant bytes (i.e. the bytes that
* hold the largest part of the value) first. These are known as big-endian
* processors. Other processors (notably the x86 family) store the most
* significant byte last. These are known as little-endian processors.
*
* Finally, to complicate matters, some other processors store the bytes in
* a rather curious order known as PDP-endian. For a 4-byte word, the 3rd
* most significant byte is stored first, then the 4th, then the 1st and
* finally the 2nd.
*
* Obviously there is a problem when these different processors communicate
* with each other, for example over networks or by using binary file formats.
* This is where these macros come in. They are typically used to convert
* values into a byte order which has been agreed on for use when
* communicating between different processors. The Internet uses what is
* known as 'network byte order' as the standard byte order (which is in
* fact the big-endian byte order).
*
* Note that the byte order conversion macros may evaluate their arguments
* multiple times, thus you should not use them with arguments which have
* side-effects.
*/
/**
* G_BYTE_ORDER:
*
* The host byte order.
* This can be either #G_LITTLE_ENDIAN or #G_BIG_ENDIAN (support for
* #G_PDP_ENDIAN may be added in future.)
*/
/**
* G_LITTLE_ENDIAN:
*
* Specifies one of the possible types of byte order.
* See #G_BYTE_ORDER.
*/
/**
* G_BIG_ENDIAN:
*
* Specifies one of the possible types of byte order.
* See #G_BYTE_ORDER.
*/
/**
* G_PDP_ENDIAN:
*
* Specifies one of the possible types of byte order
* (currently unused). See #G_BYTE_ORDER.
*/
/**
* g_htonl:
* @val: a 32-bit integer value in host byte order
*
* Converts a 32-bit integer value from host to network byte order.
*
* Returns: @val converted to network byte order
*/
/**
* g_htons:
* @val: a 16-bit integer value in host byte order
*
* Converts a 16-bit integer value from host to network byte order.
*
* Returns: @val converted to network byte order
*/
/**
* g_ntohl:
* @val: a 32-bit integer value in network byte order
*
* Converts a 32-bit integer value from network to host byte order.
*
* Returns: @val converted to host byte order.
*/
/**
* g_ntohs:
* @val: a 16-bit integer value in network byte order
*
* Converts a 16-bit integer value from network to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT_FROM_BE:
* @val: a #gint value in big-endian byte order
*
* Converts a #gint value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT_FROM_LE:
* @val: a #gint value in little-endian byte order
*
* Converts a #gint value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT_TO_BE:
* @val: a #gint value in host byte order
*
* Converts a #gint value from host byte order to big-endian.
*
* Returns: @val converted to big-endian byte order
*/
/**
* GINT_TO_LE:
* @val: a #gint value in host byte order
*
* Converts a #gint value from host byte order to little-endian.
*
* Returns: @val converted to little-endian byte order
*/
/**
* GUINT_FROM_BE:
* @val: a #guint value in big-endian byte order
*
* Converts a #guint value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT_FROM_LE:
* @val: a #guint value in little-endian byte order
*
* Converts a #guint value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT_TO_BE:
* @val: a #guint value in host byte order
*
* Converts a #guint value from host byte order to big-endian.
*
* Returns: @val converted to big-endian byte order
*/
/**
* GUINT_TO_LE:
* @val: a #guint value in host byte order
*
* Converts a #guint value from host byte order to little-endian.
*
* Returns: @val converted to little-endian byte order.
*/
/**
* GLONG_FROM_BE:
* @val: a #glong value in big-endian byte order
*
* Converts a #glong value from big-endian to the host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GLONG_FROM_LE:
* @val: a #glong value in little-endian byte order
*
* Converts a #glong value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GLONG_TO_BE:
* @val: a #glong value in host byte order
*
* Converts a #glong value from host byte order to big-endian.
*
* Returns: @val converted to big-endian byte order
*/
/**
* GLONG_TO_LE:
* @val: a #glong value in host byte order
*
* Converts a #glong value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GULONG_FROM_BE:
* @val: a #gulong value in big-endian byte order
*
* Converts a #gulong value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GULONG_FROM_LE:
* @val: a #gulong value in little-endian byte order
*
* Converts a #gulong value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GULONG_TO_BE:
* @val: a #gulong value in host byte order
*
* Converts a #gulong value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GULONG_TO_LE:
* @val: a #gulong value in host byte order
*
* Converts a #gulong value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GSIZE_FROM_BE:
* @val: a #gsize value in big-endian byte order
*
* Converts a #gsize value from big-endian to the host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GSIZE_FROM_LE:
* @val: a #gsize value in little-endian byte order
*
* Converts a #gsize value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GSIZE_TO_BE:
* @val: a #gsize value in host byte order
*
* Converts a #gsize value from host byte order to big-endian.
*
* Returns: @val converted to big-endian byte order
*/
/**
* GSIZE_TO_LE:
* @val: a #gsize value in host byte order
*
* Converts a #gsize value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GSSIZE_FROM_BE:
* @val: a #gssize value in big-endian byte order
*
* Converts a #gssize value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GSSIZE_FROM_LE:
* @val: a #gssize value in little-endian byte order
*
* Converts a #gssize value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GSSIZE_TO_BE:
* @val: a #gssize value in host byte order
*
* Converts a #gssize value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GSSIZE_TO_LE:
* @val: a #gssize value in host byte order
*
* Converts a #gssize value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GINT16_FROM_BE:
* @val: a #gint16 value in big-endian byte order
*
* Converts a #gint16 value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT16_FROM_LE:
* @val: a #gint16 value in little-endian byte order
*
* Converts a #gint16 value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT16_TO_BE:
* @val: a #gint16 value in host byte order
*
* Converts a #gint16 value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GINT16_TO_LE:
* @val: a #gint16 value in host byte order
*
* Converts a #gint16 value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GUINT16_FROM_BE:
* @val: a #guint16 value in big-endian byte order
*
* Converts a #guint16 value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT16_FROM_LE:
* @val: a #guint16 value in little-endian byte order
*
* Converts a #guint16 value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT16_TO_BE:
* @val: a #guint16 value in host byte order
*
* Converts a #guint16 value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GUINT16_TO_LE:
* @val: a #guint16 value in host byte order
*
* Converts a #guint16 value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GINT32_FROM_BE:
* @val: a #gint32 value in big-endian byte order
*
* Converts a #gint32 value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT32_FROM_LE:
* @val: a #gint32 value in little-endian byte order
*
* Converts a #gint32 value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT32_TO_BE:
* @val: a #gint32 value in host byte order
*
* Converts a #gint32 value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GINT32_TO_LE:
* @val: a #gint32 value in host byte order
*
* Converts a #gint32 value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GUINT32_FROM_BE:
* @val: a #guint32 value in big-endian byte order
*
* Converts a #guint32 value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT32_FROM_LE:
* @val: a #guint32 value in little-endian byte order
*
* Converts a #guint32 value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT32_TO_BE:
* @val: a #guint32 value in host byte order
*
* Converts a #guint32 value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GUINT32_TO_LE:
* @val: a #guint32 value in host byte order
*
* Converts a #guint32 value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GINT64_FROM_BE:
* @val: a #gint64 value in big-endian byte order
*
* Converts a #gint64 value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT64_FROM_LE:
* @val: a #gint64 value in little-endian byte order
*
* Converts a #gint64 value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GINT64_TO_BE:
* @val: a #gint64 value in host byte order
*
* Converts a #gint64 value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GINT64_TO_LE:
* @val: a #gint64 value in host byte order
*
* Converts a #gint64 value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GUINT64_FROM_BE:
* @val: a #guint64 value in big-endian byte order
*
* Converts a #guint64 value from big-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT64_FROM_LE:
* @val: a #guint64 value in little-endian byte order
*
* Converts a #guint64 value from little-endian to host byte order.
*
* Returns: @val converted to host byte order
*/
/**
* GUINT64_TO_BE:
* @val: a #guint64 value in host byte order
*
* Converts a #guint64 value from host byte order to big-endian.
*
* Returns: @val converted to big-endian
*/
/**
* GUINT64_TO_LE:
* @val: a #guint64 value in host byte order
*
* Converts a #guint64 value from host byte order to little-endian.
*
* Returns: @val converted to little-endian
*/
/**
* GUINT16_SWAP_BE_PDP:
* @val: a #guint16 value in big-endian or pdp-endian byte order
*
* Converts a #guint16 value between big-endian and pdp-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/**
* GUINT16_SWAP_LE_BE:
* @val: a #guint16 value in little-endian or big-endian byte order
*
* Converts a #guint16 value between little-endian and big-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/**
* GUINT16_SWAP_LE_PDP:
* @val: a #guint16 value in little-endian or pdp-endian byte order
*
* Converts a #guint16 value between little-endian and pdp-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/**
* GUINT32_SWAP_BE_PDP:
* @val: a #guint32 value in big-endian or pdp-endian byte order
*
* Converts a #guint32 value between big-endian and pdp-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/**
* GUINT32_SWAP_LE_BE:
* @val: a #guint32 value in little-endian or big-endian byte order
*
* Converts a #guint32 value between little-endian and big-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/**
* GUINT32_SWAP_LE_PDP:
* @val: a #guint32 value in little-endian or pdp-endian byte order
*
* Converts a #guint32 value between little-endian and pdp-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/**
* GUINT64_SWAP_LE_BE:
* @val: a #guint64 value in little-endian or big-endian byte order
*
* Converts a #guint64 value between little-endian and big-endian byte order.
* The conversion is symmetric so it can be used both ways.
*
* Returns: @val converted to the opposite byte order
*/
/* Bounds-checked integer arithmetic {{{1 */
/**
* SECTION:checkedmath
* @title: Bounds-checking integer arithmetic
* @short_description: a set of helpers for performing checked integer arithmetic
*
* GLib offers a set of macros for doing additions and multiplications
* of unsigned integers, with checks for overflows.
*
* The helpers all have three arguments. A pointer to the destination
* is always the first argument and the operands to the operation are
* the other two.
*
* Following standard GLib convention, the helpers return %TRUE in case
* of success (ie: no overflow).
*
* The helpers may be macros, normal functions or inlines. They may be
* implemented with inline assembly or compiler intrinsics where
* available.
*
* Since: 2.48
*/
/**
* g_uint_checked_add
* @dest: a pointer to the #guint destination
* @a: the #guint left operand
* @b: the #guint right operand
*
* Performs a checked addition of @a and @b, storing the result in
* @dest.
*
* If the operation is successful, %TRUE is returned. If the operation
* overflows then the state of @dest is undefined and %FALSE is
* returned.
*
* Returns: %TRUE if there was no overflow
* Since: 2.48
*/
/**
* g_uint_checked_mul
* @dest: a pointer to the #guint destination
* @a: the #guint left operand
* @b: the #guint right operand
*
* Performs a checked multiplication of @a and @b, storing the result in
* @dest.
*
* If the operation is successful, %TRUE is returned. If the operation
* overflows then the state of @dest is undefined and %FALSE is
* returned.
*
* Returns: %TRUE if there was no overflow
* Since: 2.48
*/
/**
* g_uint64_checked_add
* @dest: a pointer to the #guint64 destination
* @a: the #guint64 left operand
* @b: the #guint64 right operand
*
* Performs a checked addition of @a and @b, storing the result in
* @dest.
*
* If the operation is successful, %TRUE is returned. If the operation
* overflows then the state of @dest is undefined and %FALSE is
* returned.
*
* Returns: %TRUE if there was no overflow
* Since: 2.48
*/
/**
* g_uint64_checked_mul
* @dest: a pointer to the #guint64 destination
* @a: the #guint64 left operand
* @b: the #guint64 right operand
*
* Performs a checked multiplication of @a and @b, storing the result in
* @dest.
*
* If the operation is successful, %TRUE is returned. If the operation
* overflows then the state of @dest is undefined and %FALSE is
* returned.
*
* Returns: %TRUE if there was no overflow
* Since: 2.48
*/
/**
* g_size_checked_add
* @dest: a pointer to the #gsize destination
* @a: the #gsize left operand
* @b: the #gsize right operand
*
* Performs a checked addition of @a and @b, storing the result in
* @dest.
*
* If the operation is successful, %TRUE is returned. If the operation
* overflows then the state of @dest is undefined and %FALSE is
* returned.
*
* Returns: %TRUE if there was no overflow
* Since: 2.48
*/
/**
* g_size_checked_mul
* @dest: a pointer to the #gsize destination
* @a: the #gsize left operand
* @b: the #gsize right operand
*
* Performs a checked multiplication of @a and @b, storing the result in
* @dest.
*
* If the operation is successful, %TRUE is returned. If the operation
* overflows then the state of @dest is undefined and %FALSE is
* returned.
*
* Returns: %TRUE if there was no overflow
* Since: 2.48
*/
/* Numerical Definitions {{{1 */
/**
* SECTION:numerical
* @title: Numerical Definitions
* @short_description: mathematical constants, and floating point decomposition
*
* GLib offers mathematical constants such as #G_PI for the value of pi;
* many platforms have these in the C library, but some don't, the GLib
* versions always exist.
*
* The #GFloatIEEE754 and #GDoubleIEEE754 unions are used to access the
* sign, mantissa and exponent of IEEE floats and doubles. These unions are
* defined as appropriate for a given platform. IEEE floats and doubles are
* supported (used for storage) by at least Intel, PPC and Sparc. See
* [IEEE 754-2008](http://en.wikipedia.org/wiki/IEEE_float)
* for more information about IEEE number formats.
*/
/**
* G_IEEE754_FLOAT_BIAS:
*
* The bias by which exponents in single-precision floats are offset.
*/
/**
* G_IEEE754_DOUBLE_BIAS:
*
* The bias by which exponents in double-precision floats are offset.
*/
/**
* GFloatIEEE754:
* @v_float: the double value
*
* The #GFloatIEEE754 and #GDoubleIEEE754 unions are used to access the sign,
* mantissa and exponent of IEEE floats and doubles. These unions are defined
* as appropriate for a given platform. IEEE floats and doubles are supported
* (used for storage) by at least Intel, PPC and Sparc.
*/
/**
* GDoubleIEEE754:
* @v_double: the double value
*
* The #GFloatIEEE754 and #GDoubleIEEE754 unions are used to access the sign,
* mantissa and exponent of IEEE floats and doubles. These unions are defined
* as appropriate for a given platform. IEEE floats and doubles are supported
* (used for storage) by at least Intel, PPC and Sparc.
*/
/**
* G_E:
*
* The base of natural logarithms.
*/
/**
* G_LN2:
*
* The natural logarithm of 2.
*/
/**
* G_LN10:
*
* The natural logarithm of 10.
*/
/**
* G_PI:
*
* The value of pi (ratio of circle's circumference to its diameter).
*/
/**
* G_PI_2:
*
* Pi divided by 2.
*/
/**
* G_PI_4:
*
* Pi divided by 4.
*/
/**
* G_SQRT2:
*
* The square root of two.
*/
/**
* G_LOG_2_BASE_10:
*
* Multiplying the base 2 exponent by this number yields the base 10 exponent.
*/
/* Macros {{{1 */
/**
* SECTION:macros
* @title: Standard Macros
* @short_description: commonly-used macros
*
* These macros provide a few commonly-used features.
*/
/**
* G_OS_WIN32:
*
* This macro is defined only on Windows. So you can bracket
* Windows-specific code in "\#ifdef G_OS_WIN32".
*/
/**
* G_OS_UNIX:
*
* This macro is defined only on UNIX. So you can bracket
* UNIX-specific code in "\#ifdef G_OS_UNIX".
*/
/**
* G_DIR_SEPARATOR:
*
* The directory separator character.
* This is '/' on UNIX machines and '\' under Windows.
*/
/**
* G_DIR_SEPARATOR_S:
*
* The directory separator as a string.
* This is "/" on UNIX machines and "\" under Windows.
*/
/**
* G_IS_DIR_SEPARATOR:
* @c: a character
*
* Checks whether a character is a directory
* separator. It returns %TRUE for '/' on UNIX
* machines and for '\' or '/' under Windows.
*
* Since: 2.6
*/
/**
* G_SEARCHPATH_SEPARATOR:
*
* The search path separator character.
* This is ':' on UNIX machines and ';' under Windows.
*/
/**
* G_SEARCHPATH_SEPARATOR_S:
*
* The search path separator as a string.
* This is ":" on UNIX machines and ";" under Windows.
*/
/**
* TRUE:
*
* Defines the %TRUE value for the #gboolean type.
*/
/**
* FALSE:
*
* Defines the %FALSE value for the #gboolean type.
*/
/**
* NULL:
*
* Defines the standard %NULL pointer.
*/
/**
* MIN:
* @a: a numeric value
* @b: a numeric value
*
* Calculates the minimum of @a and @b.
*
* Returns: the minimum of @a and @b.
*/
/**
* MAX:
* @a: a numeric value
* @b: a numeric value
*
* Calculates the maximum of @a and @b.
*
* Returns: the maximum of @a and @b.
*/
/**
* ABS:
* @a: a numeric value
*
* Calculates the absolute value of @a.
* The absolute value is simply the number with any negative sign taken away.
*
* For example,
* - ABS(-10) is 10.
* - ABS(10) is also 10.
*
* Returns: the absolute value of @a.
*/
/**
* CLAMP:
* @x: the value to clamp
* @low: the minimum value allowed
* @high: the maximum value allowed
*
* Ensures that @x is between the limits set by @low and @high. If @low is
* greater than @high the result is undefined.
*
* For example,
* - CLAMP(5, 10, 15) is 10.
* - CLAMP(15, 5, 10) is 10.
* - CLAMP(20, 15, 25) is 20.
*
* Returns: the value of @x clamped to the range between @low and @high
*/
/**
* G_STRUCT_MEMBER:
* @member_type: the type of the struct field
* @struct_p: a pointer to a struct
* @struct_offset: the offset of the field from the start of the struct,
* in bytes
*
* Returns a member of a structure at a given offset, using the given type.
*
* Returns: the struct member
*/
/**
* G_STRUCT_MEMBER_P:
* @struct_p: a pointer to a struct
* @struct_offset: the offset from the start of the struct, in bytes
*
* Returns an untyped pointer to a given offset of a struct.
*
* Returns: an untyped pointer to @struct_p plus @struct_offset bytes
*/
/**
* G_STRUCT_OFFSET:
* @struct_type: a structure type, e.g. #GtkWidget
* @member: a field in the structure, e.g. @window
*
* Returns the offset, in bytes, of a member of a struct.
*
* Returns: the offset of @member from the start of @struct_type
*/
/**
* G_CONST_RETURN:
*
* If %G_DISABLE_CONST_RETURNS is defined, this macro expands
* to nothing. By default, the macro expands to const. The macro
* can be used in place of const for functions that return a value
* that should not be modified. The purpose of this macro is to allow
* us to turn on const for returned constant strings by default, while
* allowing programmers who find that annoying to turn it off. This macro
* should only be used for return values and for "out" parameters, it
* doesn't make sense for "in" parameters.
*
* Deprecated: 2.30: API providers should replace all existing uses with
* const and API consumers should adjust their code accordingly
*/
/**
* G_N_ELEMENTS:
* @arr: the array
*
* Determines the number of elements in an array. The array must be
* declared so the compiler knows its size at compile-time; this
* macro will not work on an array allocated on the heap, only static
* arrays or arrays on the stack.
*/
/* Miscellaneous Macros {{{1 */
/**
* SECTION:macros_misc
* @title: Miscellaneous Macros
* @short_description: specialized macros which are not used often
*
* These macros provide more specialized features which are not
* needed so often by application programmers.
*/
/**
* G_INLINE_FUNC:
*
* This macro used to be used to conditionally define inline functions
* in a compatible way before this feature was supported in all
* compilers. These days, GLib requires inlining support from the
* compiler, so your GLib-using programs can safely assume that the
* "inline" keywork works properly.
*
* Never use this macro anymore. Just say "static inline".
*
* Deprecated: 2.48: Use "static inline" instead
*/
/**
* G_STMT_START:
*
* Used within multi-statement macros so that they can be used in places
* where only one statement is expected by the compiler.
*/
/**
* G_STMT_END:
*
* Used within multi-statement macros so that they can be used in places
* where only one statement is expected by the compiler.
*/
/**
* G_BEGIN_DECLS:
*
* Used (along with #G_END_DECLS) to bracket header files. If the
* compiler in use is a C++ compiler, adds extern "C"
* around the header.
*/
/**
* G_END_DECLS:
*
* Used (along with #G_BEGIN_DECLS) to bracket header files. If the
* compiler in use is a C++ compiler, adds extern "C"
* around the header.
*/
/**
* G_VA_COPY:
* @ap1: the va_list variable to place a copy of @ap2 in
* @ap2: a va_list
*
* Portable way to copy va_list variables.
*
* In order to use this function, you must include string.h yourself,
* because this macro may use memmove() and GLib does not include
* string.h for you.
*/
/**
* G_STRINGIFY:
* @macro_or_string: a macro or a string
*
* Accepts a macro or a string and converts it into a string after
* preprocessor argument expansion. For example, the following code:
*
* |[<!-- language="C" -->
* #define AGE 27
* const gchar *greeting = G_STRINGIFY (AGE) " today!";
* ]|
*
* is transformed by the preprocessor into (code equivalent to):
*
* |[<!-- language="C" -->
* const gchar *greeting = "27 today!";
* ]|
*/
/**
* G_PASTE:
* @identifier1: an identifier
* @identifier2: an identifier
*
* Yields a new preprocessor pasted identifier
* @identifier1identifier2 from its expanded
* arguments @identifier1 and @identifier2. For example,
* the following code:
* |[<!-- language="C" -->
* #define GET(traveller,method) G_PASTE(traveller_get_, method) (traveller)
* const gchar *name = GET (traveller, name);
* const gchar *quest = GET (traveller, quest);
* GdkColor *favourite = GET (traveller, favourite_colour);
* ]|
*
* is transformed by the preprocessor into:
* |[<!-- language="C" -->
* const gchar *name = traveller_get_name (traveller);
* const gchar *quest = traveller_get_quest (traveller);
* GdkColor *favourite = traveller_get_favourite_colour (traveller);
* ]|
*
* Since: 2.20
*/
/**
* G_STATIC_ASSERT:
* @expr: a constant expression
*
* The G_STATIC_ASSERT() macro lets the programmer check
* a condition at compile time, the condition needs to
* be compile time computable. The macro can be used in
* any place where a typedef is valid.
*
* A typedef is generally allowed in exactly the same places that
* a variable declaration is allowed. For this reason, you should
* not use G_STATIC_ASSERT() in the middle of blocks of code.
*
* The macro should only be used once per source code line.
*
* Since: 2.20
*/
/**
* G_STATIC_ASSERT_EXPR:
* @expr: a constant expression
*
* The G_STATIC_ASSERT_EXPR() macro lets the programmer check
* a condition at compile time. The condition needs to be
* compile time computable.
*
* Unlike G_STATIC_ASSERT(), this macro evaluates to an expression
* and, as such, can be used in the middle of other expressions.
* Its value should be ignored. This can be accomplished by placing
* it as the first argument of a comma expression.
*
* |[<!-- language="C" -->
* #define ADD_ONE_TO_INT(x) \
* (G_STATIC_ASSERT_EXPR(sizeof (x) == sizeof (int)), ((x) + 1))
* ]|
*
* Since: 2.30
*/
/**
* G_GNUC_EXTENSION:
*
* Expands to __extension__ when gcc is used as the compiler. This simply
* tells gcc not to warn about the following non-standard code when compiling
* with the `-pedantic` option.
*/
/**
* G_GNUC_CHECK_VERSION:
*
* Expands to a a check for a compiler with __GNUC__ defined and a version
* greater than or equal to the major and minor numbers provided. For example,
* the following would only match on compilers such as GCC 4.8 or newer.
*
* |[<!-- language="C" -->
* #if G_GNUC_CHECK_VERSION(4, 8)
* #endif
* ]|
*
* Since: 2.42
*/
/**
* G_GNUC_CONST:
*
* Expands to the GNU C const function attribute if the compiler is gcc.
* Declaring a function as const enables better optimization of calls to
* the function. A const function doesn't examine any values except its
* parameters, and has no effects except its return value.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*
* A function that has pointer arguments and examines the data pointed to
* must not be declared const. Likewise, a function that calls a non-const
* function usually must not be const. It doesn't make sense for a const
* function to return void.
*/
/**
* G_GNUC_PURE:
*
* Expands to the GNU C pure function attribute if the compiler is gcc.
* Declaring a function as pure enables better optimization of calls to
* the function. A pure function has no effects except its return value
* and the return value depends only on the parameters and/or global
* variables.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*/
/**
* G_GNUC_MALLOC:
*
* Expands to the GNU C malloc function attribute if the compiler is gcc.
* Declaring a function as malloc enables better optimization of the function.
* A function can have the malloc attribute if it returns a pointer which is
* guaranteed to not alias with any other pointer when the function returns
* (in practice, this means newly allocated memory).
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*
* Since: 2.6
*/
/**
* G_GNUC_ALLOC_SIZE:
* @x: the index of the argument specifying the allocation size
*
* Expands to the GNU C alloc_size function attribute if the compiler
* is a new enough gcc. This attribute tells the compiler that the
* function returns a pointer to memory of a size that is specified
* by the @xth function parameter.
*
* Place the attribute after the function declaration, just before the
* semicolon.
*
* See the GNU C documentation for more details.
*
* Since: 2.18
*/
/**
* G_GNUC_ALLOC_SIZE2:
* @x: the index of the argument specifying one factor of the allocation size
* @y: the index of the argument specifying the second factor of the allocation size
*
* Expands to the GNU C alloc_size function attribute if the compiler is a
* new enough gcc. This attribute tells the compiler that the function returns
* a pointer to memory of a size that is specified by the product of two
* function parameters.
*
* Place the attribute after the function declaration, just before the
* semicolon.
*
* See the GNU C documentation for more details.
*
* Since: 2.18
*/
/**
* G_GNUC_DEPRECATED:
*
* Expands to the GNU C deprecated attribute if the compiler is gcc.
* It can be used to mark typedefs, variables and functions as deprecated.
* When called with the `-Wdeprecated-declarations` option,
* gcc will generate warnings when deprecated interfaces are used.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*
* Since: 2.2
*/
/**
* G_GNUC_DEPRECATED_FOR:
* @f: the intended replacement for the deprecated symbol,
* such as the name of a function
*
* Like %G_GNUC_DEPRECATED, but names the intended replacement for the
* deprecated symbol if the version of gcc in use is new enough to support
* custom deprecation messages.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*
* Note that if @f is a macro, it will be expanded in the warning message.
* You can enclose it in quotes to prevent this. (The quotes will show up
* in the warning, but it's better than showing the macro expansion.)
*
* Since: 2.26
*/
/**
* G_GNUC_BEGIN_IGNORE_DEPRECATIONS:
*
* Tells gcc (if it is a new enough version) to temporarily stop emitting
* warnings when functions marked with %G_GNUC_DEPRECATED or
* %G_GNUC_DEPRECATED_FOR are called. This is useful for when you have
* one deprecated function calling another one, or when you still have
* regression tests for deprecated functions.
*
* Use %G_GNUC_END_IGNORE_DEPRECATIONS to begin warning again. (If you
* are not compiling with `-Wdeprecated-declarations` then neither macro
* has any effect.)
*
* This macro can be used either inside or outside of a function body,
* but must appear on a line by itself.
*
* Since: 2.32
*/
/**
* G_GNUC_END_IGNORE_DEPRECATIONS:
*
* Undoes the effect of %G_GNUC_BEGIN_IGNORE_DEPRECATIONS, telling
* gcc to begin outputting warnings again (assuming those warnings
* had been enabled to begin with).
*
* This macro can be used either inside or outside of a function body,
* but must appear on a line by itself.
*
* Since: 2.32
*/
/**
* G_DEPRECATED:
*
* This macro is similar to %G_GNUC_DEPRECATED, and can be used to mark
* functions declarations as deprecated. Unlike %G_GNUC_DEPRECATED, it is
* meant to be portable across different compilers and must be placed
* before the function declaration.
*
* Since: 2.32
*/
/**
* G_DEPRECATED_FOR:
* @f: the name of the function that this function was deprecated for
*
* This macro is similar to %G_GNUC_DEPRECATED_FOR, and can be used to mark
* functions declarations as deprecated. Unlike %G_GNUC_DEPRECATED_FOR, it
* is meant to be portable across different compilers and must be placed
* before the function declaration.
*
* Since: 2.32
*/
/**
* G_UNAVAILABLE:
* @maj: the major version that introduced the symbol
* @min: the minor version that introduced the symbol
*
* This macro can be used to mark a function declaration as unavailable.
* It must be placed before the function declaration. Use of a function
* that has been annotated with this macros will produce a compiler warning.
*
* Since: 2.32
*/
/**
* GLIB_DISABLE_DEPRECATION_WARNINGS:
*
* A macro that should be defined before including the glib.h header.
* If it is defined, no compiler warnings will be produced for uses
* of deprecated GLib APIs.
*/
/**
* G_GNUC_NORETURN:
*
* Expands to the GNU C noreturn function attribute if the compiler is gcc.
* It is used for declaring functions which never return. It enables
* optimization of the function, and avoids possible compiler warnings.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*/
/**
* G_GNUC_UNUSED:
*
* Expands to the GNU C unused function attribute if the compiler is gcc.
* It is used for declaring functions and arguments which may never be used.
* It avoids possible compiler warnings.
*
* For functions, place the attribute after the declaration, just before the
* semicolon. For arguments, place the attribute at the beginning of the
* argument declaration.
*
* |[<!-- language="C" -->
* void my_unused_function (G_GNUC_UNUSED gint unused_argument,
* gint other_argument) G_GNUC_UNUSED;
* ]|
*
* See the GNU C documentation for more details.
*/
/**
* G_GNUC_PRINTF:
* @format_idx: the index of the argument corresponding to the
* format string (the arguments are numbered from 1)
* @arg_idx: the index of the first of the format arguments, or 0 if
* there are no format arguments
*
* Expands to the GNU C format function attribute if the compiler is gcc.
* This is used for declaring functions which take a variable number of
* arguments, with the same syntax as printf(). It allows the compiler
* to type-check the arguments passed to the function.
*
* Place the attribute after the function declaration, just before the
* semicolon.
*
* See the
* [GNU C documentation](https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-Wformat-3288)
* for more details.
*
* |[<!-- language="C" -->
* gint g_snprintf (gchar *string,
* gulong n,
* gchar const *format,
* ...) G_GNUC_PRINTF (3, 4);
* ]|
*/
/**
* G_GNUC_SCANF:
* @format_idx: the index of the argument corresponding to
* the format string (the arguments are numbered from 1)
* @arg_idx: the index of the first of the format arguments, or 0 if
* there are no format arguments
*
* Expands to the GNU C format function attribute if the compiler is gcc.
* This is used for declaring functions which take a variable number of
* arguments, with the same syntax as scanf(). It allows the compiler
* to type-check the arguments passed to the function.
*
* See the
* [GNU C documentation](https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-Wformat-3288)
* for details.
*/
/**
* G_GNUC_FORMAT:
* @arg_idx: the index of the argument
*
* Expands to the GNU C format_arg function attribute if the compiler
* is gcc. This function attribute specifies that a function takes a
* format string for a printf(), scanf(), strftime() or strfmon() style
* function and modifies it, so that the result can be passed to a printf(),
* scanf(), strftime() or strfmon() style function (with the remaining
* arguments to the format function the same as they would have been
* for the unmodified string).
*
* Place the attribute after the function declaration, just before the
* semicolon.
*
* See the GNU C documentation for more details.
*
* |[<!-- language="C" -->
* gchar *g_dgettext (gchar *domain_name, gchar *msgid) G_GNUC_FORMAT (2);
* ]|
*/
/**
* G_GNUC_NULL_TERMINATED:
*
* Expands to the GNU C sentinel function attribute if the compiler is gcc.
* This function attribute only applies to variadic functions and instructs
* the compiler to check that the argument list is terminated with an
* explicit %NULL.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*
* Since: 2.8
*/
/**
* G_GNUC_WARN_UNUSED_RESULT:
*
* Expands to the GNU C warn_unused_result function attribute if the compiler
* is gcc. This function attribute makes the compiler emit a warning if the
* result of a function call is ignored.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*
* Since: 2.10
*/
/**
* G_GNUC_FUNCTION:
*
* Expands to "" on all modern compilers, and to __FUNCTION__ on gcc
* version 2.x. Don't use it.
*
* Deprecated: 2.16: Use G_STRFUNC() instead
*/
/**
* G_GNUC_PRETTY_FUNCTION:
*
* Expands to "" on all modern compilers, and to __PRETTY_FUNCTION__
* on gcc version 2.x. Don't use it.
*
* Deprecated: 2.16: Use G_STRFUNC() instead
*/
/**
* G_GNUC_NO_INSTRUMENT:
*
* Expands to the GNU C no_instrument_function function attribute if the
* compiler is gcc. Functions with this attribute will not be instrumented
* for profiling, when the compiler is called with the
* `-finstrument-functions` option.
*
* Place the attribute after the declaration, just before the semicolon.
*
* See the GNU C documentation for more details.
*/
/**
* G_GNUC_INTERNAL:
*
* This attribute can be used for marking library functions as being used
* internally to the library only, which may allow the compiler to handle
* function calls more efficiently. Note that static functions do not need
* to be marked as internal in this way. See the GNU C documentation for
* details.
*
* When using a compiler that supports the GNU C hidden visibility attribute,
* this macro expands to __attribute__((visibility("hidden"))).
* When using the Sun Studio compiler, it expands to __hidden.
*
* Note that for portability, the attribute should be placed before the
* function declaration. While GCC allows the macro after the declaration,
* Sun Studio does not.
*
* |[<!-- language="C" -->
* G_GNUC_INTERNAL
* void _g_log_fallback_handler (const gchar *log_domain,
* GLogLevelFlags log_level,
* const gchar *message,
* gpointer unused_data);
* ]|
*
* Since: 2.6
*/
/**
* G_GNUC_MAY_ALIAS:
*
* Expands to the GNU C may_alias type attribute if the compiler is gcc.
* Types with this attribute will not be subjected to type-based alias
* analysis, but are assumed to alias with any other type, just like char.
*
* See the GNU C documentation for details.
*
* Since: 2.14
*/
/**
* G_LIKELY:
* @expr: the expression
*
* Hints the compiler that the expression is likely to evaluate to
* a true value. The compiler may use this information for optimizations.
*
* |[<!-- language="C" -->
* if (G_LIKELY (random () != 1))
* g_print ("not one");
* ]|
*
* Returns: the value of @expr
*
* Since: 2.2
*/
/**
* G_UNLIKELY:
* @expr: the expression
*
* Hints the compiler that the expression is unlikely to evaluate to
* a true value. The compiler may use this information for optimizations.
*
* |[<!-- language="C" -->
* if (G_UNLIKELY (random () == 1))
* g_print ("a random one");
* ]|
*
* Returns: the value of @expr
*
* Since: 2.2
*/
/**
* G_STRLOC:
*
* Expands to a string identifying the current code position.
*/
/**
* G_STRFUNC:
*
* Expands to a string identifying the current function.
*
* Since: 2.4
*/
/**
* G_HAVE_GNUC_VISIBILITY:
*
* Defined to 1 if gcc-style visibility handling is supported.
*/
/* g_auto(), g_autoptr() and helpers {{{1 */
/**
* g_auto:
* @TypeName: a supported variable type
*
* Helper to declare a variable with automatic cleanup.
*
* The variable is cleaned up in a way appropriate to its type when the
* variable goes out of scope. The type must support this.
*
* This feature is only supported on GCC and clang. This macro is not
* defined on other compilers and should not be used in programs that
* are intended to be portable to those compilers.
*
* This is meant to be used with stack-allocated structures and
* non-pointer types. For the (more commonly used) pointer version, see
* g_autoptr().
*
* This macro can be used to avoid having to do explicit cleanups of
* local variables when exiting functions. It often vastly simplifies
* handling of error conditions, removing the need for various tricks
* such as 'goto out' or repeating of cleanup code. It is also helpful
* for non-error cases.
*
* Consider the following example:
*
* |[
* GVariant *
* my_func(void)
* {
* g_auto(GQueue) queue = G_QUEUE_INIT;
* g_auto(GVariantBuilder) builder;
* g_auto(GStrv) strv;
*
* g_variant_builder_init (&builder, G_VARIANT_TYPE_VARDICT);
* strv = g_strsplit("a:b:c", ":", -1);
*
* ...
*
* if (error_condition)
* return NULL;
*
* ...
*
* return g_variant_builder_end (&builder);
* }
* ]|
*
* You must initialize the variable in some way -- either by use of an
* initialiser or by ensuring that an _init function will be called on
* it unconditionally before it goes out of scope.
*
* Since: 2.44
*/
/**
* g_autoptr:
* @TypeName: a supported variable type
*
* Helper to declare a pointer variable with automatic cleanup.
*
* The variable is cleaned up in a way appropriate to its type when the
* variable goes out of scope. The type must support this.
*
* This feature is only supported on GCC and clang. This macro is not
* defined on other compilers and should not be used in programs that
* are intended to be portable to those compilers.
*
* This is meant to be used to declare pointers to types with cleanup
* functions. The type of the variable is a pointer to @TypeName. You
* must not add your own '*'.
*
* This macro can be used to avoid having to do explicit cleanups of
* local variables when exiting functions. It often vastly simplifies
* handling of error conditions, removing the need for various tricks
* such as 'goto out' or repeating of cleanup code. It is also helpful
* for non-error cases.
*
* Consider the following example:
*
* |[
* gboolean
* check_exists(GVariant *dict)
* {
* g_autoptr(GVariant) dirname, basename = NULL;
* g_autofree gchar *path = NULL;
*
* dirname = g_variant_lookup_value (dict, "dirname", G_VARIANT_TYPE_STRING);
*
* if (dirname == NULL)
* return FALSE;
*
* basename = g_variant_lookup_value (dict, "basename", G_VARIANT_TYPE_STRING);
*
* if (basename == NULL)
* return FALSE;
*
* path = g_build_filename (g_variant_get_string (dirname, NULL),
* g_variant_get_string (basename, NULL),
* NULL);
*
* return g_access (path, R_OK) == 0;
* }
* ]|
*
* You must initialise the variable in some way -- either by use of an
* initialiser or by ensuring that it is assigned to unconditionally
* before it goes out of scope.
*
* See also g_auto(), g_autofree() and g_steal_pointer().
*
* Since: 2.44
*/
/**
* g_autofree:
*
* Macro to add an attribute to pointer variable to ensure automatic
* cleanup using g_free().
*
* This macro differs from g_autoptr() in that it is an attribute supplied
* before the type name, rather than wrapping the type definition. Instead
* of using a type-specific lookup, this macro always calls g_free() directly.
*
* This means it's useful for any type that is returned from
* g_malloc().
*
* Otherwise, this macro has similar constraints as g_autoptr() - only
* supported on GCC and clang, the variable must be initialized, etc.
*
* |[
* gboolean
* operate_on_malloc_buf (void)
* {
* g_autofree guint8* membuf = NULL;
*
* membuf = g_malloc (8192);
*
* /<!-- -->* Some computation on membuf *<!-- -->/
*
* /<!-- -->* membuf will be automatically freed here *<!-- -->/
* return TRUE;
* }
* ]|
*
* Since: 2.44
*/
/**
* G_DEFINE_AUTOPTR_CLEANUP_FUNC:
* @TypeName: a type name to define a g_autoptr() cleanup function for
* @func: the cleanup function
*
* Defines the appropriate cleanup function for a pointer type.
*
* The function will not be called if the variable to be cleaned up
* contains %NULL.
*
* This will typically be the _free() or _unref() function for the given
* type.
*
* With this definition, it will be possible to use g_autoptr() with
* @TypeName.
*
* |[
* G_DEFINE_AUTOPTR_CLEANUP_FUNC(GObject, g_object_unref)
* ]|
*
* This macro should be used unconditionally; it is a no-op on compilers
* where cleanup is not supported.
*
* Since: 2.44
*/
/**
* G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC:
* @TypeName: a type name to define a g_auto() cleanup function for
* @func: the clear function
*
* Defines the appropriate cleanup function for a type.
*
* This will typically be the _clear() function for the given type.
*
* With this definition, it will be possible to use g_auto() with
* @TypeName.
*
* |[
* G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(GQueue, g_queue_clear)
* ]|
*
* This macro should be used unconditionally; it is a no-op on compilers
* where cleanup is not supported.
*
* Since: 2.44
*/
/**
* G_DEFINE_AUTO_CLEANUP_FREE_FUNC:
* @TypeName: a type name to define a g_auto() cleanup function for
* @func: the free function
* @none: the "none" value for the type
*
* Defines the appropriate cleanup function for a type.
*
* With this definition, it will be possible to use g_auto() with
* @TypeName.
*
* This function will be rarely used. It is used with pointer-based
* typedefs and non-pointer types where the value of the variable
* represents a resource that must be freed. Two examples are #GStrv
* and file descriptors.
*
* @none specifies the "none" value for the type in question. It is
* probably something like %NULL or -1. If the variable is found to
* contain this value then the free function will not be called.
*
* |[
* G_DEFINE_AUTO_CLEANUP_FREE_FUNC(GStrv, g_strfreev, NULL)
* ]|
*
* This macro should be used unconditionally; it is a no-op on compilers
* where cleanup is not supported.
*
* Since: 2.44
*/
/* Windows Compatibility Functions {{{1 */
/**
* SECTION:windows
* @title: Windows Compatibility Functions
* @short_description: UNIX emulation on Windows
*
* These functions provide some level of UNIX emulation on the
* Windows platform. If your application really needs the POSIX
* APIs, we suggest you try the Cygwin project.
*/
/**
* MAXPATHLEN:
*
* Provided for UNIX emulation on Windows; equivalent to UNIX
* macro %MAXPATHLEN, which is the maximum length of a filename
* (including full path).
*/
/**
* G_WIN32_DLLMAIN_FOR_DLL_NAME:
* @static: empty or "static"
* @dll_name: the name of the (pointer to the) char array where
* the DLL name will be stored. If this is used, you must also
* include `windows.h`. If you need a more complex DLL entry
* point function, you cannot use this
*
* On Windows, this macro defines a DllMain() function that stores
* the actual DLL name that the code being compiled will be included in.
*
* On non-Windows platforms, expands to nothing.
*/
/**
* G_WIN32_HAVE_WIDECHAR_API:
*
* On Windows, this macro defines an expression which evaluates to
* %TRUE if the code is running on a version of Windows where the wide
* character versions of the Win32 API functions, and the wide character
* versions of the C library functions work. (They are always present in
* the DLLs, but don't work on Windows 9x and Me.)
*
* On non-Windows platforms, it is not defined.
*
* Since: 2.6
*/
/**
* G_WIN32_IS_NT_BASED:
*
* On Windows, this macro defines an expression which evaluates to
* %TRUE if the code is running on an NT-based Windows operating system.
*
* On non-Windows platforms, it is not defined.
*
* Since: 2.6
*/
/* Epilogue {{{1 */
/* vim: set foldmethod=marker: */
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