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POStatic member object initialization
 

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    <p>I'm trying to implement a template for states machines in C++, but I'm not sure how to handle static object members. Each state machine would be defined by its state variables and its transitions (which are structs). For instance:</p> <pre><code>// stm.h template &lt;class T&gt; struct transition { ... transition relevant data depending on state variables T ... }; template &lt;class T&gt; class stm { T *stv; // state variables static struct transition&lt;T&gt; *transitions; // I would like to have only one copy of transitions for stm's of type T ... etc ... }; </code></pre> <p>Now, suppose I'm trying to implement the stm foo:</p> <pre><code>// foo_defs.h struct foo_stv { char a; int b; }; // foo_transitions.h // Note that I'm using a different file to keep everything in order #include "stm.h" #include "foo_defs.h" struct transition&lt;struct foo_stv&gt; foo_transitions[] = { { ... trans1 ... }, ..., { ... transN ... } }; // foo_stm.h #include "stm.h" #include "foo_defs.h" #include "foo_transitions.h" class foo_stm { stm&lt;struct foo_stv&gt; stm; struct foo_stv stv; ... other data ... }; </code></pre> <p>Ok. So each instance of foo_stm should have a different set of state variables, but all instances should use the same transitions. The question is, how should I define/declare <code>stm&lt;struct foo_stv&gt;</code> in order to use <code>foo_transitions</code> as its class level <code>transitions</code> member?</p> <p>Also any advice about C++ coding customs is welcome, since I come from the C coding world and just getting started with some C++ mechanics.</p> <p><strong>EDIT</strong>: Just to make clear my question, I guess you should forget about the stm logic and focus on the following: What's the correct way of doing something like...</p> <pre><code>foo_stm::stm.transitions = foo_transitions; </code></pre>
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    1. COwhy not a singleton pattern ? The problem will be that you can not initialize the static member except in the cpp, OR if you use recent c++.
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    2. CO*"Also any advice about C++ coding customs is welcome, since I come from the C coding world and just getting started with some C++ mechanics*" OK: `struct` keyword is not needed in C++ (Im talking about the sentences like `stm<struct foo_stv>`. The only difference between `class` and `struct` is that the default scope of class members is private, in struct is public.
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    3. CO"each instance of foo_stm should have a different set of state variables, but all instances should use the same transitions." How can you have different state variables and the same transitions?
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