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POWhy does C++ not have a const constructor?
 

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  1. POWhy does C++ not have a const constructor?
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    <p>(<em>Edit: Heavy change because previous example was flawed, which may make some answers/comments seem odd)</em></p> <p>This might be an overly contrived, but the following is legal because of lack of const constructor:</p> <pre><code> class Cheater { public: Cheater(int avalue) : cheaterPtr(this) //conceptually odd legality in const Cheater ctor , value(avalue) {} Cheater&amp; getCheaterPtr() const {return *cheaterPtr;} int value; private: Cheater * cheaterPtr; }; int main() { const Cheater cheater(7); //Initialize the value to 7 cheater.value = 4; //good, illegal cheater.getCheaterPtr().value = 4; //oops, legal return 0; } </code></pre> <p>It seems like providing a const constructor a thing would be as easy technically as const methods, and be analogous to a const overload.</p> <p><em>Note: I'm not looking for '<code>Image( const Data &amp; data ) const</code>' but rather '<code>const Image( const Data &amp; data) const</code>'</em></p> <p>So:</p> <ul> <li>Why is the const constructor absent in C++?</li> </ul> <p>Here's some related material for context:</p> <ul> <li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/1995/N0798.htm" rel="noreferrer">http://www.open-std.org/jtc1/sc22/wg21/docs/papers/1995/N0798.htm</a></li> <li><a href="https://stackoverflow.com/questions/1699307/how-to-deal-with-initialization-of-non-const-member-in-const-object/6936079#6936079">How to deal with initialization of non-const reference member in const object?</a></li> <li><a href="https://stackoverflow.com/questions/5656664/c-classes-const-and-strange-syntax">C++, Classes, Const, and strange syntax</a></li> </ul>
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    1. CO"The const constructor" isn't _absent_ in C++, it's something you made up just now.
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    2. COAlso, what would be the advantages of this?
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    3. COSeth: This must make sense in some mindset where copy constructors take pointers instead of references. Not sure where.
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