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POGood style for handling constructor failure of critical object
 

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  1. POGood style for handling constructor failure of critical object
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    <p>I'm trying to decide between two ways of instantiating an object &amp; handling any constructor exceptions for an object that is critical to my program, i.e. if construction fails the program can't continue.</p> <p>I have a class SimpleMIDIOut that wraps basic Win32 MIDI functions. It will open a MIDI device in the constructor and close it in the destructor. It will throw an exception inherited from std::exception in the constructor if the MIDI device cannot be opened.</p> <p>Which of the following ways of catching constructor exceptions for this object would be more in line with C++ best practices</p> <p>Method 1 - Stack allocated object, only in scope inside try block</p> <pre><code>#include &lt;iostream&gt; #include "simplemidiout.h" int main() { try { SimpleMIDIOut myOut; //constructor will throw if MIDI device cannot be opened myOut.PlayNote(60,100); //..... //myOut goes out of scope outside this block //so basically the whole program has to be inside //this block. //On the plus side, it's on the stack so //destructor that handles object cleanup //is called automatically, more inline with RAII idiom? } catch(const std::exception&amp; e) { std::cout &lt;&lt; e.what() &lt;&lt; std::endl; std::cin.ignore(); return 1; } std::cin.ignore(); return 0; } </code></pre> <p>Method 2 - Pointer to object, heap allocated, nicer structured code?</p> <pre><code>#include &lt;iostream&gt; #include "simplemidiout.h" int main() { SimpleMIDIOut *myOut; try { myOut = new SimpleMIDIOut(); } catch(const std::exception&amp; e) { std::cout &lt;&lt; e.what() &lt;&lt; std::endl; delete myOut; return 1; } myOut-&gt;PlayNote(60,100); std::cin.ignore(); delete myOut; return 0; } </code></pre> <p>I like the look of the code in Method 2 better, don't have to jam my whole program into a try block, but Method 1 creates the object on the stack so C++ manages the object's life time, which is more in tune with RAII philosophy isn't it?</p> <p>I'm still a novice at this so any feedback on the above is much appreciated. If there's an even better way to check for/handle constructor failure in a siatuation like this please let me know.</p>
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    1. CO+1 for a well-asked first question.
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      1. USrazlebe
 

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