<!-- ##### SECTION Title ##### -->
Miscellaneous Macros

<!-- ##### SECTION Short_Description ##### -->
specialised macros which are not used often.

<!-- ##### SECTION Long_Description ##### -->
<para>
These macros provide more specialized features which are not needed so often
by application programmers.
</para>

<!-- ##### SECTION See_Also ##### -->
<para>

</para>

<!-- ##### MACRO G_INLINE_FUNC ##### -->
<para>
Used to declare inline functions. If inline functions are not supported on
the particular platform, the macro evaluates to the empty string.
</para>



<!-- ##### MACRO G_STMT_START ##### -->
<para>
Used within multi-statement macros so that they can be used in places where
only one statement is expected by the compiler.
</para>



<!-- ##### MACRO G_STMT_END ##### -->
<para>
Used within multi-statement macros so that they can be used in places where
only one statement is expected by the compiler.
</para>



<!-- ##### MACRO G_BEGIN_DECLS ##### -->
<para>
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.
</para>



<!-- ##### MACRO G_END_DECLS ##### -->
<para>
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.
</para>



<!-- ##### MACRO G_N_ELEMENTS ##### -->
<para>
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.
</para>

@arr: the array


<!-- ##### MACRO G_VA_COPY ##### -->
<para>
Portable way to copy <type>va_list</type> variables.
</para>
<para>
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.
</para>

<!-- # Unused Parameters # -->
@ap1: the <type>va_list</type> variable to place a copy of @ap2 in.
@ap2: a <type>va_list</type>.


<!-- ##### MACRO G_STRINGIFY ##### -->
<para>

</para>

@macro_or_string: 


<!-- ##### MACRO G_GNUC_EXTENSION ##### -->
<para>
Expands to "__extension__" when GNU C is used as the compiler.
This simply tells GNU C not to warn about the following non-standard code
when compiling with the -pedantic option.
</para>



<!-- ##### MACRO G_GNUC_CONST ##### -->
<para>
Expands to the GNU C const function attribute if the compiler is GNU C.
This enables optimization of the function.
See the GNU C documentation for details. 
</para>



<!-- ##### MACRO G_GNUC_NORETURN ##### -->
<para>
Expands to the GNU C noreturn function attribute if the compiler is GNU C.
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. 
</para>



<!-- ##### MACRO G_GNUC_UNUSED ##### -->
<para>
Expands to the GNU C unused function attribute if the compiler is GNU C.
It is used for declaring functions which may never be used.
It avoids possible compiler warnings. See the GNU C documentation for details. 
</para>



<!-- ##### MACRO G_GNUC_PURE ##### -->
<para>

</para>



<!-- ##### MACRO G_GNUC_PRINTF ##### -->
<para>
Expands to the GNU C format function attribute if the compiler is GNU C.
This is used for declaring functions which take a variable number of
arguments, with the same syntax as <function>printf()</function>.
It allows the compiler to type-check the arguments passed to the function.
See the GNU C documentation for details. 
</para>

@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.


<!-- ##### MACRO G_GNUC_SCANF ##### -->
<para>
Expands to the GNU C format function attribute if the compiler is GNU C.
This is used for declaring functions which take a variable number of
arguments, with the same syntax as <function>scanf()</function>.
It allows the compiler to type-check the arguments passed to the function.
See the GNU C documentation for details. 
</para>

@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.


<!-- ##### MACRO G_GNUC_FORMAT ##### -->
<para>
Expands to the GNU C format_arg function attribute if the compiler is GNU C.
This is used for declaring functions which take a variable number of
parameters, like <function>printf()</function> and
<function>scanf()</function>. See the GNU C documentation for details. 

FIXME: I can't find this in my GNU C documentation. Take out?
</para>

@arg_idx: the index of the argument.


<!-- ##### MACRO G_GNUC_FUNCTION ##### -->
<para>
Expands to the GNU C __FUNCTION__ variable if the compiler is GNU C,
or "" if it isn't.
The GNU C __FUNCTION__ variable contains the name of the current function.
See the GNU C documentation for details. 
</para>



<!-- ##### MACRO G_GNUC_PRETTY_FUNCTION ##### -->
<para>
Expands to the GNU C __PRETTY_FUNCTION__ variable if the compiler is GNU C,
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. 
</para>



<!-- ##### MACRO G_STRLOC ##### -->
<para>

</para>



<!-- ##### MACRO G_GINT16_FORMAT ##### -->
<para>
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.
</para>

<para>
<informalexample>
<programlisting>
gint16 in;
gint32 out;
sscanf ("42", "%" G_GINT16_FORMAT, &amp;in)
out = in * 1000;
g_print ("%" G_GINT32_FORMAT, out);
</programlisting>
</informalexample>
</para>



<!-- ##### MACRO G_GUINT16_FORMAT ##### -->
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type #guint16. See also #G_GINT16_FORMAT.
</para>



<!-- ##### MACRO G_GINT32_FORMAT ##### -->
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type #gint32. See also #G_GINT16_FORMAT.
</para>



<!-- ##### MACRO G_GUINT32_FORMAT ##### -->
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type #guint32. See also #G_GINT16_FORMAT.
</para>



<!-- ##### MACRO G_GINT64_FORMAT ##### -->
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type #gint64. See also #G_GINT16_FORMAT.
</para>

<note>
<para>
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.
</para>
</note>



<!-- ##### MACRO G_GUINT64_FORMAT ##### -->
<para>
This is the platform dependent conversion specifier for scanning and
printing values of type #guint64. See also #G_GINT16_FORMAT.
</para>

<note>
<para>
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.
</para>
</note>



