docs/reference/glib/tmpl/macros_misc.sgml

   1 <!-- ##### SECTION Title ##### -->
   2 Miscellaneous Macros
   3
   4 <!-- ##### SECTION Short_Description ##### -->
   5 specialised macros which are not used often.
   6
   7 <!-- ##### SECTION Long_Description ##### -->
   8 <para>
   9 These macros provide more specialized features which are not needed so often
  10 by application programmers.
  11 </para>
  12
  13 <!-- ##### SECTION See_Also ##### -->
  14 <para>
  15
  16 </para>
  17
  18 <!-- ##### MACRO G_INLINE_FUNC ##### -->
  19 <para>
  20 Used to declare inline functions. If inline functions are not supported on
  21 the particular platform, the macro evaluates to the empty string.
  22 </para>
  23
  24
  25
  26 <!-- ##### MACRO G_STMT_START ##### -->
  27 <para>
  28 Used within multi-statement macros so that they can be used in places where
  29 only one statement is expected by the compiler.
  30 </para>
  31
  32
  33
  34 <!-- ##### MACRO G_STMT_END ##### -->
  35 <para>
  36 Used within multi-statement macros so that they can be used in places where
  37 only one statement is expected by the compiler.
  38 </para>
  39
  40
  41
  42 <!-- ##### MACRO G_BEGIN_DECLS ##### -->
  43 <para>
  44 Used (along with #G_END_DECLS) to bracket header files. If the
  45 compiler in use is a C++ compiler, adds 'extern "C"' around the header.
  46 </para>
  47
  48
  49
  50 <!-- ##### MACRO G_END_DECLS ##### -->
  51 <para>
  52 Used (along with #G_BEGIN_DECLS) to bracket header files. If the
  53 compiler in use is a C++ compiler, adds 'extern "C"' around the header.
  54 </para>
  55
  56
  57
  58 <!-- ##### MACRO G_N_ELEMENTS ##### -->
  59 <para>
  60 Determines the number of elements in an array. The array must be
  61 declared so the compiler knows its size at compile-time; this
  62 macro will not work on an array allocated on the heap, only static
  63 arrays or arrays on the stack.
  64 </para>
  65
  66 @arr: the array
  67
  68
  69 <!-- ##### MACRO G_VA_COPY ##### -->
  70 <para>
  71 Portable way to copy <type>va_list</type> variables.
  72 </para>
  73 <para>
  74 In order to use this function, you must include string.h yourself,
  75 because this macro may use memmove() and GLib does not include
  76 string.h for you.
  77 </para>
  78
  79 <!-- # Unused Parameters # -->
  80 @ap1: the <type>va_list</type> variable to place a copy of @ap2 in.
  81 @ap2: a <type>va_list</type>.
  82
  83
  84 <!-- ##### MACRO G_STRINGIFY ##### -->
  85 <para>
  86
  87 </para>
  88
  89 @macro_or_string:
  90
  91
  92 <!-- ##### MACRO G_GNUC_EXTENSION ##### -->
  93 <para>
  94 Expands to "__extension__" when GNU C is used as the compiler.
  95 This simply tells GNU C not to warn about the following non-standard code
  96 when compiling with the -pedantic option.
  97 </para>
  98
  99
 100
 101 <!-- ##### MACRO G_GNUC_CONST ##### -->
 102 <para>
 103 Expands to the GNU C const function attribute if the compiler is GNU C.
 104 This enables optimization of the function.
 105 See the GNU C documentation for details.
 106 </para>
 107
 108
 109
 110 <!-- ##### MACRO G_GNUC_NORETURN ##### -->
 111 <para>
 112 Expands to the GNU C noreturn function attribute if the compiler is GNU C.
 113 It is used for declaring functions which never return.
 114 It enables optimization of the function, and avoids possible compiler
 115 warnings. See the GNU C documentation for details.
 116 </para>
 117
 118
 119
 120 <!-- ##### MACRO G_GNUC_UNUSED ##### -->
 121 <para>
 122 Expands to the GNU C unused function attribute if the compiler is GNU C.
 123 It is used for declaring functions which may never be used.
 124 It avoids possible compiler warnings. See the GNU C documentation for details.
 125 </para>
 126
 127
 128
 129 <!-- ##### MACRO G_GNUC_PURE ##### -->
 130 <para>
 131
 132 </para>
 133
 134
 135
 136 <!-- ##### MACRO G_GNUC_PRINTF ##### -->
 137 <para>
 138 Expands to the GNU C format function attribute if the compiler is GNU C.
 139 This is used for declaring functions which take a variable number of
 140 arguments, with the same syntax as <function>printf()</function>.
 141 It allows the compiler to type-check the arguments passed to the function.
 142 See the GNU C documentation for details.
 143 </para>
 144
 145 @format_idx: the index of the argument corresponding to the format string.
 146 (The arguments are numbered from 1).
 147 @arg_idx: the index of the first of the format arguments.
 148
 149
 150 <!-- ##### MACRO G_GNUC_SCANF ##### -->
 151 <para>
 152 Expands to the GNU C format function attribute if the compiler is GNU C.
 153 This is used for declaring functions which take a variable number of
 154 arguments, with the same syntax as <function>scanf()</function>.
 155 It allows the compiler to type-check the arguments passed to the function.
 156 See the GNU C documentation for details.
 157 </para>
 158
 159 @format_idx: the index of the argument corresponding to the format string.
 160 (The arguments are numbered from 1).
 161 @arg_idx: the index of the first of the format arguments.
 162
 163
 164 <!-- ##### MACRO G_GNUC_FORMAT ##### -->
 165 <para>
 166 Expands to the GNU C format_arg function attribute if the compiler is GNU C.
 167 This is used for declaring functions which take a variable number of
 168 parameters, like <function>printf()</function> and
 169 <function>scanf()</function>. See the GNU C documentation for details.
 170
 171 FIXME: I can't find this in my GNU C documentation. Take out?
 172 </para>
 173
 174 @arg_idx: the index of the argument.
 175
 176
 177 <!-- ##### MACRO G_GNUC_FUNCTION ##### -->
 178 <para>
 179 Expands to the GNU C __FUNCTION__ variable if the compiler is GNU C,
 180 or "" if it isn't.
 181 The GNU C __FUNCTION__ variable contains the name of the current function.
 182 See the GNU C documentation for details.
 183 </para>
 184
 185
 186
 187 <!-- ##### MACRO G_GNUC_PRETTY_FUNCTION ##### -->
 188 <para>
 189 Expands to the GNU C __PRETTY_FUNCTION__ variable if the compiler is GNU C,
 190 or "" if it isn't.
 191 The GNU C __PRETTY_FUNCTION__ variable contains the name of the current
 192 function. For a C program this is the same as the __FUNCTION__ variable
 193 but for C++ it also includes extra information such as the class
 194 and function prototype. See the GNU C documentation for details.
 195 </para>
 196
 197
 198
 199 <!-- ##### MACRO G_STRLOC ##### -->
 200 <para>
 201
 202 </para>
 203
 204
 205
 206 <!-- ##### MACRO G_GINT16_FORMAT ##### -->
 207 <para>
 208 This is the platform dependent conversion specifier for scanning and
 209 printing values of type #gint16. It is a string literal, but doesn't
 210 include the percent-sign, such that you can add precision and length
 211 modifiers between percent-sign and conversion specifier.
 212 </para>
 213
 214 <para>
 215 <informalexample>
 216 <programlisting>
 217 gint16 in;
 218 gint32 out;
 219 sscanf ("42", "%" G_GINT16_FORMAT, &amp;in)
 220 out = in * 1000;
 221 g_print ("%" G_GINT32_FORMAT, out);
 222 </programlisting>
 223 </informalexample>
 224 </para>
 225
 226
 227
 228 <!-- ##### MACRO G_GUINT16_FORMAT ##### -->
 229 <para>
 230 This is the platform dependent conversion specifier for scanning and
 231 printing values of type #guint16. See also #G_GINT16_FORMAT.
 232 </para>
 233
 234
 235
 236 <!-- ##### MACRO G_GINT32_FORMAT ##### -->
 237 <para>
 238 This is the platform dependent conversion specifier for scanning and
 239 printing values of type #gint32. See also #G_GINT16_FORMAT.
 240 </para>
 241
 242
 243
 244 <!-- ##### MACRO G_GUINT32_FORMAT ##### -->
 245 <para>
 246 This is the platform dependent conversion specifier for scanning and
 247 printing values of type #guint32. See also #G_GINT16_FORMAT.
 248 </para>
 249
 250
 251
 252 <!-- ##### MACRO G_GINT64_FORMAT ##### -->
 253 <para>
 254 This is the platform dependent conversion specifier for scanning and
 255 printing values of type #gint64. See also #G_GINT16_FORMAT.
 256 </para>
 257
 258 <note>
 259 <para>
 260 Some platforms do not support scanning and printing 64 bit integers,
 261 even though the types are supported. On such platforms G_GINT64_FORMAT
 262 is not defined.
 263 </para>
 264 </note>
 265
 266
 267
 268 <!-- ##### MACRO G_GUINT64_FORMAT ##### -->
 269 <para>
 270 This is the platform dependent conversion specifier for scanning and
 271 printing values of type #guint64. See also #G_GINT16_FORMAT.
 272 </para>
 273
 274 <note>
 275 <para>
 276 Some platforms do not support scanning and printing 64 bit integers,
 277 even though the types are supported. On such platforms G_GUINT64_FORMAT
 278 is not defined.
 279 </para>
 280 </note>
 281
 282
 283