Re: Author of Visual C++ 2005 STL ???

#include <stdio.h>
#include <vector>

class ClassWithCopyConstructor
{
public:
 ClassWithCopyConstructor();
 ~ClassWithCopyConstructor();
 ClassWithCopyConstructor(const ClassWithCopyConstructor
&CWCC);
};

ClassWithCopyConstructor::~ClassWithCopyConstructor()
{
 printf("Destructed!\n");
}

ClassWithCopyConstructor::ClassWithCopyConstructor()
{
 printf("Default Constructed!\n");
}

ClassWithCopyConstructor::ClassWithCopyConstructor(const
ClassWithCopyConstructor& CWCC)
{
 printf("Copy Constructed!\n");
}

std::vector<ClassWithCopyConstructor> Test;

int main()
{
 ClassWithCopyConstructor Temp;
 Test.push_back(Temp); // Copies Twice !!!
 return 0;
}

(1) Make me exactly one Object // This works
(2) Copy the Object exactly once to the std::vector // this
copy constructs twice, not what I asked for
(3) Destroy the exactly two objects that you constructed //
This also destroys the unnecessary extra copy

There is no inherent fundamental reason why asking it to
copy once necessarily requires it to make two copies within
the scope of every possible design of the implementation of
the push_back() function. There definitely exists possible
implementations of the push_back() function that only need
to do a single copy construction, even when the need for
memory re-allocation is considered.