/* * Copyright © 2011 Red Hat, Inc * * SPDX-License-Identifier: LGPL-2.1-or-later * * 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 . * * 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. * * Note that depending on the platform and build configuration, the format * macros might not be compatible with the system provided printf() function, * because GLib might use a different printf() implementation internally. * The format macros will always work with GLib API (like g_print()), and with * any C99 compatible printf() implementation. */ /** * gboolean: * * A standard boolean type. * Variables of this type should only contain the value * %TRUE or %FALSE. * * Never directly compare the contents of a #gboolean variable with the values * %TRUE or %FALSE. Use `if (condition)` to check a #gboolean is "true", instead * of `if (condition == TRUE)`. Likewise use `if (!condition)` to check a * #gboolean is "false". * * There is no validation when assigning to a #gboolean variable and so it could * contain any value represented by a #gint. This is why the use of `if * (condition)` is recommended. All non-zero values in C evaluate to "true". */ /** * 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_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_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"; * |[ * 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. * * |[ * 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_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_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 POSIX type `off_t` as if compiling with * `_FILE_OFFSET_BITS` set to 64. #goffset is always 64 bits wide, even on * 32-bit architectures. * 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: * |[ * 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: * |[ * 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: * |[ * 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 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_DARWIN: * * This macro is defined only on Apple operating systems (macOS or iOS). * So you can bracket Apple-specific code in `\#ifdef G_OS_DARWIN`. * * Note that %G_OS_UNIX is also set. * * Since: 2.76 */ /** * 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_APPROX_VALUE: * @a: a numeric value * @b: a numeric value * @epsilon: a numeric value that expresses the tolerance between @a and @b * * Evaluates to a truth value if the absolute difference between @a and @b is * smaller than @epsilon, and to a false value otherwise. * * For example, * - `G_APPROX_VALUE (5, 6, 2)` evaluates to true * - `G_APPROX_VALUE (3.14, 3.15, 0.001)` evaluates to false * - `G_APPROX_VALUE (n, 0.f, FLT_EPSILON)` evaluates to true if `n` is within * the single precision floating point epsilon from zero * * Returns: %TRUE if the two values are within the desired range * * Since: 2.58 */ /** * 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_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_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. * * Each invocation of `G_VA_COPY (ap1, ap2)` must be matched with a * corresponding `va_end (ap1)` call in the same function. */ /** * 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: * * |[ * #define AGE 27 * const gchar *greeting = G_STRINGIFY (AGE) " today!"; * ]| * * is transformed by the preprocessor into (code equivalent to): * * |[ * 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: * |[ * #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: * |[ * 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. * * |[ * #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: * @major: major version to check against * @minor: minor version to check against * * Expands to 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. * * |[ * #if G_GNUC_CHECK_VERSION(4, 8) * #endif * ]| * * Since: 2.42 */ /** * 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. Both this macro and the corresponding * %G_GNUC_END_IGNORE_DEPRECATIONS are considered statements, so they * should not be used around branching or loop conditions; for instance, * this use is invalid: * * |[ * G_GNUC_BEGIN_IGNORE_DEPRECATIONS * if (check == some_deprecated_function ()) * G_GNUC_END_IGNORE_DEPRECATIONS * { * do_something (); * } * ]| * * and you should move the deprecated section outside the condition * * |[ * * // Solution A * some_data_t *res; * * G_GNUC_BEGIN_IGNORE_DEPRECATIONS * res = some_deprecated_function (); * G_GNUC_END_IGNORE_DEPRECATIONS * * if (check == res) * { * do_something (); * } * * // Solution B * G_GNUC_BEGIN_IGNORE_DEPRECATIONS * if (check == some_deprecated_function ()) * { * do_something (); * } * G_GNUC_END_IGNORE_DEPRECATIONS * ]| * * |[ * static void * test_deprecated_function (void) * { * G_GNUC_BEGIN_IGNORE_DEPRECATIONS * g_assert_cmpint (my_mistake (), ==, 42); * G_GNUC_END_IGNORE_DEPRECATIONS * } * ]| * * 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. * * |[ * G_DEPRECATED * int my_mistake (void); * ]| * * 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. * * |[ * G_DEPRECATED_FOR(my_replacement) * int my_mistake (void); * ]| * * 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_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. * * |[ * 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_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. * * |[ * 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. * * |[ * 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. * The way to clean up the type must have been defined using one of the macros * G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC() or G_DEFINE_AUTO_CLEANUP_FREE_FUNC(). * * 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. * The way to clean up the type must have been defined using the macro * G_DEFINE_AUTOPTR_CLEANUP_FUNC(). * * 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_autolist: * @TypeName: a supported variable type * * Helper to declare a list variable with automatic deep cleanup. * * The list is deeply freed, in a way appropriate to the specified 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 lists of a type with a cleanup * function. The type of the variable is a `GList *`. 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. * * See also g_autoslist(), g_autoptr() and g_steal_pointer(). * * Since: 2.56 */ /** * g_autoslist: * @TypeName: a supported variable type * * Helper to declare a singly linked list variable with automatic deep cleanup. * * The list is deeply freed, in a way appropriate to the specified 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 lists of a type with a cleanup * function. The type of the variable is a `GSList *`. 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. * * See also g_autolist(), g_autoptr() and g_steal_pointer(). * * Since: 2.56 */ /** * g_autoqueue: * @TypeName: a supported variable type * * Helper to declare a double-ended queue variable with automatic deep cleanup. * * The queue is deeply freed, in a way appropriate to the specified 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 queues of a type with a cleanup * function. The type of the variable is a `GQueue *`. 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. * * See also g_autolist(), g_autoptr() and g_steal_pointer(). * * Since: 2.62 */ /** * 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 */ /* Warnings and Assertions {{{1 */ /** * SECTION:warnings * @title: Warnings and Assertions * @short_description: warnings and assertions to use in runtime code * * GLib defines several warning functions and assertions which can be used to * warn of programmer errors when calling functions, and print error messages * from command line programs. * * The g_return_if_fail(), g_return_val_if_fail(), g_return_if_reached() and * g_return_val_if_reached() macros are intended as pre-condition assertions, to * be used at the top of a public function to check that the function’s * arguments are acceptable. Any failure of such a pre-condition assertion is * considered a programming error on the part of the caller of the public API, * and the program is considered to be in an undefined state afterwards. They * are similar to the libc assert() function, but provide more context on * failures. * * For example: * |[ * gboolean * g_dtls_connection_shutdown (GDtlsConnection *conn, * gboolean shutdown_read, * gboolean shutdown_write, * GCancellable *cancellable, * GError **error) * { * // local variable declarations * * g_return_val_if_fail (G_IS_DTLS_CONNECTION (conn), FALSE); * g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), FALSE); * g_return_val_if_fail (error == NULL || *error == NULL, FALSE); * * // function body * * return return_val; * } * ]| * * g_print(), g_printerr() and g_set_print_handler() are intended to be used for * output from command line applications, since they output to standard output * and standard error by default — whereas functions like g_message() and * g_log() may be redirected to special purpose message windows, files, or the * system journal. */ /* 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: */