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<title>Generated state ids</title><link rel="stylesheet" href="boostbook.css" type="text/css"><meta name="generator" content="DocBook XSL-NS Stylesheets V1.75.2"><link rel="home" href="index.html" title="Meta State Machine (MSM) V2.10"><link rel="up" href="ch06.html" title="Chapter 6. Internals"><link rel="prev" href="ch06s02.html" title="Frontend / Backend interface"><link rel="next" href="ch06s04.html" title="Metaprogramming tools"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"> Generated state ids </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch06s02.html">Prev</a> </td><th width="60%" align="center">Chapter 6. Internals</th><td width="20%" align="right"> <a accesskey="n" href="ch06s04.html">Next</a></td></tr></table><hr></div><div class="sect1" title="Generated state ids"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="d0e4180"></a><span class="command"><strong><a name="internals-state-id"></a></strong></span> Generated state ids </h2></div></div></div><p>Normally, one does not need to know the ids are generated for all the states
of a state machine, unless for debugging purposes, like the pstate function does
in the tutorials in order to display the name of the current state. This section
will show how to automatically display typeid-generated names, but these are not
very readable on all platforms, so it can help to know how the ids are
generated. The ids are generated using the transition table, from the “Start”
column up to down, then from the “Next” column, up to down, as shown in the next
image: </p><p><span class="inlinemediaobject"><img src="../images/AnnexA.jpg" width="90%"></span></p><p>Stopped will get id 0, Open id 1, ErrorMode id 6 and SleepMode (seen only in
the “Next” column) id 7. If you have some implicitly created states, like
transition-less initial states or states created using the explicit_creation
typedef, these will be added as a source at the end of the transition table. If
you have submachine states, a row will be added for them at the end of the
table, after the automatically or explicitly created states, which can change
their id. The next help you will need for debugging would be to call the
current_state method of the state_machine class, then the display_type helper to
generate a readable name from the id. If you do not want to go through the
transition table to fill an array of names, the library provides another helper,
fill_state_names, which, given an array of sufficient size (please see next
section to know how many states are defined in the state machine), will fill it
with typeid-generated names. </p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch06s02.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch06.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch06s04.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Frontend / Backend
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