Miscellaneous Macros specialized macros which are not used often. These macros provide more specialized features which are not needed so often by application programmers. Used to declare inline functions. If inline functions are not supported on the particular platform, the macro evaluates to the empty string. Used within multi-statement macros so that they can be used in places where only one statement is expected by the compiler. Used within multi-statement macros so that they can be used in places where only one statement is expected by the compiler. 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. 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. 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. @arr: the array 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. @ap1: the va_list variable to place a copy of @ap2 in. @ap2: a va_list. Accepts a macro or a string and converts it into a string. @macro_or_string: a macro or a string. 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. Expands to the GNU C const function attribute if the compiler is gcc. Declaring a function as const enables better optimization of the function. A const function doesn't examine any values except its parameters, and has no effects except its return value. See the GNU C documentation for 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. 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 option, the compiler will generate warnings when deprecated interfaces are used. See the GNU C documentation for details. @Since: 2.2 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. See the GNU C documentation for details. Expands to the GNU C unused function attribute if the compiler is gcc. It is used for declaring functions which may never be used. It avoids possible compiler warnings. See the GNU C documentation for details. Expands to the GNU C pure function attribute if the compiler is gcc. Declaring a function as pure enables better optimization of 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. See the GNU C documentation for details. 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. See the GNU C documentation for details. gint g_snprintf (gchar *string, gulong n, gchar const *format, ...) G_GNUC_PRINTF (3, 4); @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. 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 for details. @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. 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). See the GNU C documentation for details. gchar *g_dgettext (gchar *domain_name, gchar *msgid) G_GNUC_FORMAT (2); @arg_idx: the index of the argument. Expands to the GNU C __FUNCTION__ variable if the compiler is gcc, or "" if it isn't. The GNU C __FUNCTION__ variable contains the name of the current function. See the GNU C documentation for details. Expands to the GNU C __PRETTY_FUNCTION__ variable if the compiler is gcc, or "" if it isn't. The GNU C __PRETTY_FUNCTION__ variable contains the name of the current function. For a C program this is the same as the __FUNCTION__ variable but for C++ it also includes extra information such as the class and function prototype. See the GNU C documentation for details. 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. See the GNU C documentation for details. 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"); @expr: the expression @Since: 2.2 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"); @expr: the expression @Since: 2.2 Expands to a string identifying the current code position. The platform dependent length modifier for constructing printf() conversion specifiers for 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 and append a conversion specifier. The following example prints "0x7b"; gint16 value = 123; g_print ("%#" G_GINT16_MODIFIER "x", value); @Since: 2.4 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); This is the platform dependent conversion specifier for scanning and printing values of type #guint16. See also #G_GINT16_FORMAT. The platform dependent length modifier for constructing printf() conversion specifiers for values of type #gint32. See also #G_GINT16_MODIFIER. @Since: 2.4 This is the platform dependent conversion specifier for scanning and printing values of type #gint32. See also #G_GINT16_FORMAT. This is the platform dependent conversion specifier for scanning and printing values of type #guint32. See also #G_GINT16_FORMAT. The platform dependent length modifier for constructing printf() conversion specifiers for values of type #gint64. See also #G_GINT16_MODIFIER. 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 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_strtoull() instead. 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_strtoull() instead.