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POHow to protect an array definition againt incomplete initialization with non-zero values?
 

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  1. POHow to protect an array definition againt incomplete initialization with non-zero values?
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    <p>I have a global array, which is indexed by the values of an enum, which has an element representing number of values. The array must be initialized by a special value, which unfortunately is not a 0.</p> <pre><code>enum { A, B, C, COUNT }; extern const int arr[COUNT]; </code></pre> <p>In a .cpp file:</p> <pre><code>const int arr[COUNT] = { -1, -1, -1 }; </code></pre> <p>The enum is occasionally changed: new values added, some get removed. The error in my code, which I just fixed was an insufficient number of initialization values, which caused the rest of the array to be initialized with zeroes. I would like to put a safeguard against this kind of error.</p> <p>The problem is to either guarantee that the <code>arr</code> is always completely initialized with the special value (the <code>-1</code> in the example) or to break compilation to get the developers attention, so the array can be updated manually.</p> <p>The recent C++ standards are not available (old ms compilers and some proprietary junk). Templates can be used, to an extent. STL and Boost are strongly prohibited (don't ask), but I wont mind to copy or to reimplement the needed parts.</p> <p>If it turns out to be impossible, I will have to consider changing the special value to be 0, but I would like to avoid that: the special value (the <code>-1</code>) might be a bit too special and encoded implicitly in the rest of the code.</p> <p>I would like to avoid DSL and code generation: the primary build system is jam on ms windows and it is major PITA to get anything generated there.</p>
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    1. COCan you change `arr` from type `const int[COUNT]` to a class type?
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    2. CO@aschepler No. The values must be known in compile time. No runtime initialization possible, if you wanted to suggest that.
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    3. COhttp://stackoverflow.com/questions/2978259/programmatically-create-static-arrays-at-compile-time-in-c
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      1. USRyan Haining
 

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