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<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
-
- This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
- project.
-
- Copyright (C) 1998-2018 OpenLink Software
-
- This project is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by the
- Free Software Foundation; only version 2 of the License, dated June 1991.
-
- This program 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
- General Public License for more details.
-
- You should have received a copy of the GNU General Public License along
- with this program; if not, write to the Free Software Foundation, Inc.,
- 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-
-
-->
<refentry id="fn_udt_implements_method">
<refmeta>
<refentrytitle>udt_implements_method</refentrytitle>
<refmiscinfo>type</refmiscinfo>
</refmeta>
<refnamediv>
<refname>udt_implements_method</refname>
<refpurpose>provides a handle to the first method with specific name in a
user defined type.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis id="fsyn_udt_implements_method">
<funcprototype id="fproto_udt_implements_method">
<funcdef>any <function>udt_implements_method</function></funcdef>
<paramdef>in <parameter>udt</parameter> any</paramdef>
<paramdef>in <parameter>method_name</parameter> varchar</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 id="desc_udt_implements_method">
<title>Description</title>
<para>This returns a non-zero value (true) if the udt has an instance method
with a name equal to the value of method_name. For methods with the same
name, but with different signatures this function will return the handle
of the first method in order of definition. If a method is not found, 0
will be returned. The return value can be used to call the method using
the indirect call statement. In which case an instance should be passed
as a first argument to the indirect call statement.</para>
</refsect1>
<refsect1 id="params_udt_implements_method">
<title>Parameters</title>
<refsect2><title>udt</title>
<para>Type name as varchar or a type instance.</para>
</refsect2>
<refsect2><title>method_name</title>
<para>The requested method name as a varchar.</para>
</refsect2>
</refsect1>
<refsect1 id="ret_udt_implements_method"><title>Return Types</title>
<para>An integer will be returned. If the named method is not contained
within the user defined type 0 (false) will be returned. Otherwise an
integer representing the handle to first definition of a contained method
with that name will be returned.</para>
</refsect1>
<!--
<refsect1 id="errors_udt_implements_method">
<title>Errors</title>
<para>This function can generate the following errors:</para>
<errorcode></errorcode>
</refsect1>
-->
<refsect1 id="examples_udt_implements_method">
<title>Examples</title>
<example id="ex_udt_implements_method"><title>Finding methods within a UDT</title>
<para>This example demonstrates how one might go about utilizing the
handle of a method if found within a user defined type.</para>
<screen><![CDATA[
....
declare mtd any;
declare inst SER_UDT;
inst := new SER_UDT ();
mtd := udt_implements_method (inst, 'NEGATE');
if (mtd <> 0)
return call (mtd) (inst);
else
signal ('42000', 'No method NEGATE');
....
]]></screen>
</example>
</refsect1>
<refsect1 id="seealso_udt_implements_method">
<title>See Also</title>
<para><link linkend="fn_udt_get"><function>udt_get()</function></link></para>
<para><link linkend="fn_udt_defines_field"><function>udt_defines_field()</function></link></para>
<para><link linkend="fn_udt_instance_of"><function>udt_instance_of()</function></link></para>
<para><link linkend="fn_udt_set"><function>udt_set()</function></link></para>
</refsect1>
</refentry>
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