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5ae6bcb728
It needs to be in a separate page because it’s all macros and they have no type/class associated with them. Signed-off-by: Philip Withnall <philip@tecnocode.co.uk> Helps: #3037
281 lines
10 KiB
C
281 lines
10 KiB
C
/* GObject - GLib Type, Object, Parameter and Signal Library
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* Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
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*
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* SPDX-License-Identifier: LGPL-2.1-or-later
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General
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* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*
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* gvaluecollector.h: GValue varargs stubs
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*/
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#ifndef __G_VALUE_COLLECTOR_H__
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#define __G_VALUE_COLLECTOR_H__
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#include <glib-object.h>
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G_BEGIN_DECLS
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/* we may want to add aggregate types here some day, if requested
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* by users. the basic C types are covered already, everything
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* smaller than an int is promoted to an integer and floats are
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* always promoted to doubles for varargs call constructions.
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*/
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enum /*< skip >*/
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{
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G_VALUE_COLLECT_INT = 'i',
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G_VALUE_COLLECT_LONG = 'l',
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G_VALUE_COLLECT_INT64 = 'q',
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G_VALUE_COLLECT_DOUBLE = 'd',
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G_VALUE_COLLECT_POINTER = 'p'
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};
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/* vararg union holding actual values collected
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*/
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/**
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* GTypeCValue:
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* @v_int: the field for holding integer values
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* @v_long: the field for holding long integer values
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* @v_int64: the field for holding 64 bit integer values
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* @v_double: the field for holding floating point values
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* @v_pointer: the field for holding pointers
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*
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* A union holding one collected value.
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*/
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union _GTypeCValue
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{
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gint v_int;
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glong v_long;
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gint64 v_int64;
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gdouble v_double;
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gpointer v_pointer;
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};
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/**
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* G_VALUE_COLLECT_INIT:
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* @value: a #GValue return location. @value must contain only 0 bytes.
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* @_value_type: the #GType to use for @value.
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* @var_args: the va_list variable; it may be evaluated multiple times
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* @flags: flags which are passed on to the collect_value() function of
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* the #GTypeValueTable of @value.
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* @__error: a #gchar** variable that will be modified to hold a g_new()
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* allocated error messages if something fails
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*
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* Collects a variable argument value from a `va_list`.
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*
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* We have to implement the varargs collection as a macro, because on some
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* systems `va_list` variables cannot be passed by reference.
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*
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* Since: 2.24
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*/
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#define G_VALUE_COLLECT_INIT(value, _value_type, var_args, flags, __error) \
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G_STMT_START { \
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GTypeValueTable *g_vci_vtab; \
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G_VALUE_COLLECT_INIT2(value, g_vci_vtab, _value_type, var_args, flags, __error); \
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} G_STMT_END
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/**
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* G_VALUE_COLLECT_INIT2:
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* @value: a #GValue return location. @value must contain only 0 bytes.
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* @g_vci_vtab: a #GTypeValueTable pointer that will be set to the value table
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* for @_value_type
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* @_value_type: the #GType to use for @value.
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* @var_args: the va_list variable; it may be evaluated multiple times
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* @flags: flags which are passed on to the collect_value() function of
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* the #GTypeValueTable of @value.
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* @__error: a #gchar** variable that will be modified to hold a g_new()
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* allocated error messages if something fails
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*
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* A variant of G_VALUE_COLLECT_INIT() that provides the #GTypeValueTable
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* to the caller.
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*
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* Since: 2.74
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*/
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#define G_VALUE_COLLECT_INIT2(value, g_vci_vtab, _value_type, var_args, flags, __error) \
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G_STMT_START { \
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GValue *g_vci_val = (value); \
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guint g_vci_flags = (flags); \
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const gchar *g_vci_collect_format; \
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GTypeCValue g_vci_cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \
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guint g_vci_n_values = 0; \
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g_vci_vtab = g_type_value_table_peek (_value_type); \
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g_vci_collect_format = g_vci_vtab->collect_format; \
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g_vci_val->g_type = _value_type; /* value_meminit() from gvalue.c */ \
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while (*g_vci_collect_format) \
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{ \
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GTypeCValue *g_vci_cvalue = g_vci_cvalues + g_vci_n_values++; \
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\
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switch (*g_vci_collect_format++) \
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{ \
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case G_VALUE_COLLECT_INT: \
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g_vci_cvalue->v_int = va_arg ((var_args), gint); \
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break; \
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case G_VALUE_COLLECT_LONG: \
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g_vci_cvalue->v_long = va_arg ((var_args), glong); \
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break; \
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case G_VALUE_COLLECT_INT64: \
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g_vci_cvalue->v_int64 = va_arg ((var_args), gint64); \
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break; \
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case G_VALUE_COLLECT_DOUBLE: \
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g_vci_cvalue->v_double = va_arg ((var_args), gdouble); \
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break; \
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case G_VALUE_COLLECT_POINTER: \
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g_vci_cvalue->v_pointer = va_arg ((var_args), gpointer); \
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break; \
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default: \
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g_assert_not_reached (); \
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} \
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} \
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*(__error) = g_vci_vtab->collect_value (g_vci_val, \
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g_vci_n_values, \
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g_vci_cvalues, \
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g_vci_flags); \
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} G_STMT_END
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/**
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* G_VALUE_COLLECT:
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* @value: a #GValue return location. @value is supposed to be initialized
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* according to the value type to be collected
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* @var_args: the va_list variable; it may be evaluated multiple times
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* @flags: flags which are passed on to the collect_value() function of
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* the #GTypeValueTable of @value.
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* @__error: a #gchar** variable that will be modified to hold a g_new()
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* allocated error messages if something fails
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*
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* Collects a variable argument value from a `va_list`.
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*
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* We have to implement the varargs collection as a macro, because on some systems
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* `va_list` variables cannot be passed by reference.
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*
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* Note: If you are creating the @value argument just before calling this macro,
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* you should use the G_VALUE_COLLECT_INIT() variant and pass the uninitialized
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* #GValue. That variant is faster than G_VALUE_COLLECT().
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*/
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#define G_VALUE_COLLECT(value, var_args, flags, __error) G_STMT_START { \
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GValue *g_vc_value = (value); \
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GType g_vc_value_type = G_VALUE_TYPE (g_vc_value); \
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GTypeValueTable *g_vc_vtable = g_type_value_table_peek (g_vc_value_type); \
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\
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if (g_vc_vtable->value_free) \
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g_vc_vtable->value_free (g_vc_value); \
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memset (g_vc_value->data, 0, sizeof (g_vc_value->data)); \
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\
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G_VALUE_COLLECT_INIT(value, g_vc_value_type, var_args, flags, __error); \
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} G_STMT_END
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/**
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* G_VALUE_COLLECT_SKIP:
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* @_value_type: the #GType of the value to skip
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* @var_args: the va_list variable; it may be evaluated multiple times
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*
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* Skip an argument of type @_value_type from @var_args.
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*/
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#define G_VALUE_COLLECT_SKIP(_value_type, var_args) \
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G_STMT_START { \
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GTypeValueTable *g_vcs_vtable = g_type_value_table_peek (_value_type); \
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const gchar *g_vcs_collect_format = g_vcs_vtable->collect_format; \
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\
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while (*g_vcs_collect_format) \
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{ \
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switch (*g_vcs_collect_format++) \
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{ \
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case G_VALUE_COLLECT_INT: \
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va_arg ((var_args), gint); \
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break; \
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case G_VALUE_COLLECT_LONG: \
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va_arg ((var_args), glong); \
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break; \
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case G_VALUE_COLLECT_INT64: \
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va_arg ((var_args), gint64); \
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break; \
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case G_VALUE_COLLECT_DOUBLE: \
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va_arg ((var_args), gdouble); \
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break; \
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case G_VALUE_COLLECT_POINTER: \
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va_arg ((var_args), gpointer); \
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break; \
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default: \
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g_assert_not_reached (); \
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} \
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} \
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} G_STMT_END
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/**
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* G_VALUE_LCOPY:
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* @value: a #GValue to store into the @var_args; this must be initialized
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* and set
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* @var_args: the va_list variable; it may be evaluated multiple times
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* @flags: flags which are passed on to the lcopy_value() function of
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* the #GTypeValueTable of @value.
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* @__error: a #gchar** variable that will be modified to hold a g_new()
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* allocated error message if something fails
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*
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* Stores a value’s value into one or more argument locations from a `va_list`.
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*
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* This is the inverse of G_VALUE_COLLECT().
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*/
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#define G_VALUE_LCOPY(value, var_args, flags, __error) \
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G_STMT_START { \
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const GValue *g_vl_value = (value); \
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guint g_vl_flags = (flags); \
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GType g_vl_value_type = G_VALUE_TYPE (g_vl_value); \
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GTypeValueTable *g_vl_vtable = g_type_value_table_peek (g_vl_value_type); \
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const gchar *g_vl_lcopy_format = g_vl_vtable->lcopy_format; \
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GTypeCValue g_vl_cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \
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guint g_vl_n_values = 0; \
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\
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while (*g_vl_lcopy_format) \
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{ \
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GTypeCValue *g_vl_cvalue = g_vl_cvalues + g_vl_n_values++; \
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\
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switch (*g_vl_lcopy_format++) \
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{ \
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case G_VALUE_COLLECT_INT: \
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g_vl_cvalue->v_int = va_arg ((var_args), gint); \
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break; \
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case G_VALUE_COLLECT_LONG: \
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g_vl_cvalue->v_long = va_arg ((var_args), glong); \
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break; \
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case G_VALUE_COLLECT_INT64: \
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g_vl_cvalue->v_int64 = va_arg ((var_args), gint64); \
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break; \
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case G_VALUE_COLLECT_DOUBLE: \
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g_vl_cvalue->v_double = va_arg ((var_args), gdouble); \
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break; \
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case G_VALUE_COLLECT_POINTER: \
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g_vl_cvalue->v_pointer = va_arg ((var_args), gpointer); \
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break; \
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default: \
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g_assert_not_reached (); \
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} \
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} \
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*(__error) = g_vl_vtable->lcopy_value (g_vl_value, \
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g_vl_n_values, \
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g_vl_cvalues, \
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g_vl_flags); \
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} G_STMT_END
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/**
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* G_VALUE_COLLECT_FORMAT_MAX_LENGTH:
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*
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* The maximal number of #GTypeCValues which can be collected for a
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* single #GValue.
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*/
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#define G_VALUE_COLLECT_FORMAT_MAX_LENGTH (8)
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G_END_DECLS
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#endif /* __G_VALUE_COLLECTOR_H__ */
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