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POOverloading operator=() with callback
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  1. POOverloading operator=() with callback
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    copied!<p>I have a template <code>Property</code> which wraps a data and provides other services. This template is specialized for basic data (float, int_32, bool...) and there exists another specilization for vectors of basic types. Something like:</p> <pre><code>template&lt;typename T&gt; Property : public PropertyBase { public: // Base types specilization. void operator=(T const &amp; data); } template&lt;typename T&gt; Property&lt;std::vector&lt;T&gt; &gt; : public PropertyBase { public: // Specilization for vectors of base types. T const &amp; operator[](std::size_t i) const; } </code></pre> <p>On the specilization for basic data I have overloaded <code>operator=</code> so that a callback is called after the data was changed. On the specilization for vectors I have overloaded <code>operator[]</code> to get indexed access to the ith element of the vector.</p> <p>Now I would like to get a similar behavior that I have for <code>operator=</code> on basic types but with my specialization for vectors. I am stuck though. What I would like to do is something like:</p> <pre><code>Property&lt;std::vector&lt;float&gt; &gt; myProp; myProp[5] = 5.21f; </code></pre> <p>and expect the callback to be called after the assignement happened.</p> <p>The problem is that <code>myProp[5]</code> returns a float, and the callback mechanism is not defined for floats but Property.</p> <p>Of course I can write an indexed setter function such as</p> <pre><code>template&lt;typename T&gt; Property&lt;std::vector&lt;T&gt; &gt; : public PropertyBase { public: // Specilization for vectors of base types. T const &amp; operator[](std::size_t i) const; void set(int i, T const &amp; newValue); } </code></pre> <p>But with the setter the syntax is not as clean as I would expect.</p> <p>I can also call the callback in <code>operator[]</code> but then the callback is called before the assigment, not after.</p> <p>Anyone has an idea to get this clean syntax while still being able to call my callback after the assigment?</p> <p>Thanks!</p> <p><strong>PS:</strong> note that my <code>Property</code> templates are more complex than what is written and do check whether T is a base type or not (which is not done here) but this is not relevant for my question.</p>
 

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