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Asked: 2026-05-11T01:45:36+00:00

The following code demonstrates a weird problem I have in a Turbo C++ Explorer

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The following code demonstrates a weird problem I have in a Turbo C++ Explorer project. One of the three stack objects in D::D() is not destroyed after going out of scope.

This only happens if compiled in release mode, the auto_ptrs a_ and b_ are of different types and the exception thrown doesn’t inherit from std::exception. It appears to work just fine in VC++ 2005 and C++ Builder 2009. I did install the BDS2006 Update 2, the hotfix rollup and hotfix 12.

Is it my code or the compiler? Do you know of a fix? Not being able to reliably use auto_ptr in a VCL project would be quite inconvenient. 

#include <memory> #include <stdexcept> #include <iostream>  typedef std::exception my_error; // will work fine if replaced with line below //class my_error : public std::exception {};  class A {}; class B {};  class C { public:     C(int id) : id_(id) { std::cout << 'C::C() ' << id_ << std::endl; };     ~C() { std::cout << 'C::~C() ' << id_ << std::endl; }; private:     int id_; };  class D { public:     D()     {         C c1(1);         C c2(2);         C c3(3);          throw my_error();     };  private:     std::auto_ptr<A> a_;     std::auto_ptr<B> b_; // will work fine if replaced with line below //  std::auto_ptr<A> b_; //  std::auto_ptr<C> c_; // see expected output };  #pragma argsused int main(int argc, char* argv[]) {     try     {         D d;     }     catch (...)     {         std::cout << 'caught exception' << std::endl;     }      return 0; }

Expected:

 C::C() 1 C::C() 2 C::C() 3 C::~C() 3 C::~C() 2 C::~C() 1 caught exception

Got:

 C::C() 1 C::C() 2 C::C() 3 C::~C() 2 C::~C() 1 caught exception

Got (with line ‘// std::auto_ptr<C> c_;‘ uncommented):

 C::C() 1 C::C() 2 C::C() 3 C::~C() 1 caught exception

Edit: Made suggested changes

Edit 2:
I just tested it with C++ Builder 2007 (11.0.2902.10471), which shows the same problem. The release configuration works as soon as I check the ‘Debug information’ box in Project -> Options -> C++ Compiler -> Debugging. It surprises me that the executable gets smaller with ‘Debug information’ enabled (down to 31.5 KB from 39.5 KB ).

Edit 3:
In Turbo C++ Explorer (C++ Builder 2006) (10.0.2288.42451) the release configuration works if I uncheck the ‘Inline function expansion (-vi)’ box in Project -> Options -> C++ Compiler -> Debugging. Replacing the first line (#include <memory>) with the following code makes it work, too. 

#pragma option push -vi- #include <memory> #pragma option pop
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1 Answer

  1. This appears to be a compiler bug. I just ran the same sample in VS2008SP1 and got the expected output.

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