<?xml version='1.0'?>
<html xmlns='http://www.w3.org/1999/xhtml'
      xmlns:math='http://www.w3.org/1998/Math/MathML'
>
<head>
<title>Replacing the CppAD Error Handler</title>
<meta name="description" id="description" content="Replacing the CppAD Error Handler"/>
<meta name="keywords" id="keywords" content=" error handler replace assert exception parallel Errorhandler "/>
<style type='text/css'>
body { color : black }
body { background-color : white }
A:link { color : blue }
A:visited { color : purple }
A:active { color : purple }
</style>
<script type='text/javascript' language='JavaScript' src='_errorhandler_xml.js'>
</script>
</head>
<body>
<table><tr>
<td>
<a href="http://www.coin-or.org/CppAD/" target="_top"><img border="0" src="_image.gif"/></a>
</td>
<td><a href="library.xml" target="_top">Prev</a>
</td><td><a href="error_handler.cpp.xml" target="_top">Next</a>
</td><td>
<select onchange='choose_across0(this)'>
<option>Index-&gt;</option>
<option>contents</option>
<option>reference</option>
<option>index</option>
<option>search</option>
<option>external</option>
</select>
</td>
<td>
<select onchange='choose_up0(this)'>
<option>Up-&gt;</option>
<option>CppAD</option>
<option>library</option>
<option>ErrorHandler</option>
</select>
</td>
<td>
<select onchange='choose_down2(this)'>
<option>CppAD-&gt;</option>
<option>Install</option>
<option>Introduction</option>
<option>AD</option>
<option>ADFun</option>
<option>preprocessor</option>
<option>multi_thread</option>
<option>library</option>
<option>ipopt_solve</option>
<option>Example</option>
<option>speed</option>
<option>Appendix</option>
</select>
</td>
<td>
<select onchange='choose_down1(this)'>
<option>library-&gt;</option>
<option>ErrorHandler</option>
<option>NearEqual</option>
<option>speed_test</option>
<option>SpeedTest</option>
<option>time_test</option>
<option>NumericType</option>
<option>CheckNumericType</option>
<option>SimpleVector</option>
<option>CheckSimpleVector</option>
<option>nan</option>
<option>pow_int</option>
<option>Poly</option>
<option>LuDetAndSolve</option>
<option>RombergOne</option>
<option>RombergMul</option>
<option>Runge45</option>
<option>Rosen34</option>
<option>OdeErrControl</option>
<option>OdeGear</option>
<option>OdeGearControl</option>
<option>CppAD_vector</option>
<option>thread_alloc</option>
<option>index_sort</option>
<option>BenderQuad</option>
<option>opt_val_hes</option>
<option>LuRatio</option>
</select>
</td>
<td>
<select onchange='choose_down0(this)'>
<option>ErrorHandler-&gt;</option>
<option>error_handler.cpp</option>
<option>cppad_assert</option>
</select>
</td>
<td>
<select onchange='choose_current0(this)'>
<option>Headings-&gt;</option>
<option>Syntax</option>
<option>Constructor</option>
<option>---..Parallel Mode</option>
<option>Call</option>
<option>info</option>
<option>handler</option>
<option>known</option>
<option>line</option>
<option>file</option>
<option>exp</option>
<option>msg</option>
<option>Example</option>
</select>
</td>
</tr></table><br/>
<center><b><big><big>Replacing the CppAD Error Handler</big></big></b></center>
<br/>
<b><big><a name="Syntax" id="Syntax">Syntax</a></big></b>

<br/>

<code><font color="blue"><span style='white-space: nowrap'>ErrorHandler&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>info</span></font></i><font color="blue"><span style='white-space: nowrap'>(</span></font><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i><font color="blue"><span style='white-space: nowrap'>)<br/>
</span></font></code>

<code><font color="blue"><span style='white-space: nowrap'>ErrorHandler::Call(</span></font><i><font color="black"><span style='white-space: nowrap'>known</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>line</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>file</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>exp</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>msg</span></font></i><font color="blue"><span style='white-space: nowrap'>)<br/>
</span></font></code>
<br/>
<b><big><a name="Constructor" id="Constructor">Constructor</a></big></b>
<br/>
When you construct a <code><font color="blue">ErrorHandler</font></code> object,
the current CppAD error handler is replaced by 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
.
When the object is destructed, the previous CppAD error handler is restored.

<br/>
<br/>
<b><a name="Constructor.Parallel Mode" id="Constructor.Parallel Mode">Parallel Mode</a></b>


<br/>
The <code><font color="blue">ErrorHandler</font></code> constructor and destructor cannot be called in
<a href="ta_in_parallel.xml" target="_top"><span style='white-space: nowrap'>parallel</span></a>
 execution mode.
Furthermore, this rule is not abided by, a raw C++ <code><font color="blue">assert</font></code>,
instead of one that uses this error handler, will be generated.

<br/>
<br/>
<b><big><a name="Call" id="Call">Call</a></big></b>
<br/>
When <code><font color="blue">ErrorHandler::Call</font></code> is called,
the current CppAD error handler is used to report an error.
This starts out as a default error handler and can be replaced
using the <code><font color="blue">ErrorHandler</font></code> constructor. 

<br/>
<br/>
<b><big><a name="info" id="info">info</a></big></b>
<br/>
The object 
<code><i><font color="black"><span style='white-space: nowrap'>info</span></font></i></code>
 is used to store information
that is necessary to restore the previous CppAD error handler.
This is done when the destructor for 
<code><i><font color="black"><span style='white-space: nowrap'>info</span></font></i></code>
 is called.


<br/>
<br/>
<b><big><a name="handler" id="handler">handler</a></big></b>
<br/>
The argument 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;void&#xA0;(*</span></font><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i><font color="blue"><span style='white-space: nowrap'>)&#xA0;<br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;(bool,&#xA0;int,&#xA0;const&#xA0;char&#xA0;*,&#xA0;const&#xA0;char&#xA0;*,&#xA0;const&#xA0;char&#xA0;*);<br/>
</span></font></code>
When an error is detected,
it is called with the syntax

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i><font color="blue"><span style='white-space: nowrap'>&#xA0;(</span></font><i><font color="black"><span style='white-space: nowrap'>known</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>line</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>file</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>exp</span></font></i><font color="blue"><span style='white-space: nowrap'>,&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>msg</span></font></i><font color="blue"><span style='white-space: nowrap'>)<br/>
</span></font></code>
This routine should not return; i.e., upon detection of the error,
the routine calling 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 does not know how to proceed.

<br/>
<br/>
<b><big><a name="known" id="known">known</a></big></b>
<br/>
The 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 argument 
<code><i><font color="black"><span style='white-space: nowrap'>known</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;bool&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>known</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
If it is true, the error being reported is from a know problem.

<br/>
<br/>
<b><big><a name="line" id="line">line</a></big></b>
<br/>
The 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 argument 
<code><i><font color="black"><span style='white-space: nowrap'>line</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;int&#xA0;</span></font><i><font color="black"><span style='white-space: nowrap'>line</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
It reports the source code line number where the error is detected. 

<br/>
<br/>
<b><big><a name="file" id="file">file</a></big></b>
<br/>
The 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 argument 
<code><i><font color="black"><span style='white-space: nowrap'>file</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;const&#xA0;char&#xA0;*</span></font><i><font color="black"><span style='white-space: nowrap'>file</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
and is a <code><font color="blue">'\0'</font></code> terminated character vector.
It reports the source code file where the error is detected. 

<br/>
<br/>
<b><big><a name="exp" id="exp">exp</a></big></b>
<br/>
The 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 argument 
<code><i><font color="black"><span style='white-space: nowrap'>exp</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;const&#xA0;char&#xA0;*</span></font><i><font color="black"><span style='white-space: nowrap'>exp</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
and is a <code><font color="blue">'\0'</font></code> terminated character vector.
It is a source code boolean expression that should have been true, 
but is false,
and thereby causes this call to 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
.

<br/>
<br/>
<b><big><a name="msg" id="msg">msg</a></big></b>
<br/>
The 
<code><i><font color="black"><span style='white-space: nowrap'>handler</span></font></i></code>
 argument 
<code><i><font color="black"><span style='white-space: nowrap'>msg</span></font></i></code>
 has prototype

<code><font color="blue"><span style='white-space: nowrap'><br/>
&#xA0;&#xA0;&#xA0;&#xA0;&#xA0;const&#xA0;char&#xA0;*</span></font><i><font color="black"><span style='white-space: nowrap'>msg</span></font></i><font color="blue"><span style='white-space: nowrap'><br/>
</span></font></code>
and is a <code><font color="blue">'\0'</font></code> terminated character vector.
It reports the meaning of the error from the C++ programmers point of view.


<br/>
<br/>
<b><big><a name="Example" id="Example">Example</a></big></b>
<br/>
The file
<a href="error_handler.cpp.xml" target="_top"><span style='white-space: nowrap'>error_handler.cpp</span></a>

contains an example and test a test of using this routine.
It returns true if it succeeds and false otherwise.


<hr/>Input File: cppad/error_handler.hpp

</body>
</html>
