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POoverloading new/delete problem
 

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  1. POoverloading new/delete problem
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    <p>This is my scenario, Im trying to overload new and delete globally. I have written my allocator class in a file called allocator.h. And what I am trying to achieve is that if a file is including this header file, my version of new and delete should be used.</p> <p>So in a header file "allocator.h" i have declared the two functions </p> <pre><code>extern void* operator new(std::size_t size); extern void operator delete(void *p, std::size_t size); </code></pre> <p>I the same header file I have a class that does all the allocator stuff,</p> <pre><code>class SmallObjAllocator { ... }; </code></pre> <p>I want to call this class from the new and delete functions and I would like the class to be static, so I have done this:</p> <pre><code>template&lt;unsigned dummy&gt; struct My_SmallObjectAllocatorImpl { static SmallObjAllocator myAlloc; }; template&lt;unsigned dummy&gt; SmallObjAllocator My_SmallObjectAllocatorImpl&lt;dummy&gt;::myAlloc(DEFAULT_CHUNK_SIZE, MAX_OBJ_SIZE); typedef My_SmallObjectAllocatorImpl&lt;0&gt; My_SmallObjectAllocator; </code></pre> <p>and in the cpp file it looks like this: allocator.cc</p> <pre><code>void* operator new(std::size_t size) { std::cout &lt;&lt; "using my new" &lt;&lt; std::endl; if(size &gt; MAX_OBJ_SIZE) return malloc(size); else return My_SmallObjectAllocator::myAlloc.allocate(size); } void operator delete(void *p, std::size_t size) { if(size &gt; MAX_OBJ_SIZE) free(p); else My_SmallObjectAllocator::myAlloc.deallocate(p, size); } </code></pre> <p>The problem is when I try to call the constructor for the class SmallObjAllocator which is a static object. For some reason the compiler are calling my overloaded function new when initializing it. So it then tries to use My_SmallObjectAllocator::myAlloc.deallocate(p, size); which is not defined so the program crashes.</p> <p>So why are the compiler calling new when I define a static object? and how can I solve it?</p>
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    1. UShidayat
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    1. PO
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    1. COI don't get the purpose of the template construct. Why not make SmallObjAllocator a singleton and create the object in allocator.cc?
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      1. POoverloading new/delete problem
      1. USMichael Ulm
    2. COAs a guess, he wants the option of doing `My_SmallObjectAllocator<1>` at some point down the line, and getting a second allocator.
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      1. POoverloading new/delete problem
      1. USDennis Zickefoose
    3. COWhat happens in `SmallObjectAllocator`'s constructor?
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      1. POoverloading new/delete problem
      1. USDennis Zickefoose
 

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