Re: vector::pop_back issue
Sarath <CSarath@gmail.com> wrote:
at the time class destruction, application error occurs. Seems the
heap was corrupted with the pop_back operation on empty vector.
the code failed to execute in Visual C++ 6 and 2008. but worked fine
in DevCPP. I admit that the pop function should check for empty
vector. but still the different behavior concludes, it's a bug in
Microsoft STL Implementation
As far as I know, the result of calling pop_back() on an empty container
is undefined. As such, no implementation could possibly be broken when
you do such a thing because the implementation can do whatever it wants.
template<class T>
class TestStack
Why not use std::stack?
{
public:
TestStack<T>() { _stack.reserve(1024); }
~TestStack<T>() { _stack.clear(); }
T pop()
{
T Obj = _stack.back();
_stack.pop_back();
return Obj;
}
What are you going to do in the above if T's copy constructor throws
when Obj is returned? You don't get the popped object and it is no
longer in the container.
Better would be to maintain command-query separation. Use back() to
access the last element and pop_back when it is no longer needed.
void push( const T& element )
{ _stack.push_back( element ); }
bool clear( void ) { _stack.clear(); }
private:
deque<T> _stack;
};
int main( void )
{
TestStack<int> StackObj;
StackObj.pop();
StackObj.push( 10 );
StackObj.push( 20 );
StackObj.push( 30 );
StackObj.push( 40 );
return 0;
}
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