<div>holy! you learn something every day. you can call the destructor of an object (before destruction)</div>
<div> </div>
<div>this is a trap for me because i dont clean up my variables in destructors.</div>
<div>
<p>class A {<br>public:<br> A() {<br> counter = 0;<br>}<br>~A() {<br> counter++;<br> std::cout << "~A(): " << counter << std::endl;<br>}<br>int counter;<br>};</p>
<p>int main(int argc, char* argv[])<br>{<br> A a;<br> a.~A();<br> return 0;<br>}</p></div>
<div>NOTE: destructor gets called twice.</div>
<div>(so it's probably a good idea to NULL pointers in destructors)<br><br> </div>
<div><span class="gmail_quote">On 7/11/06, <b class="gmail_sendername">bringiton bringiton</b> <<a href="mailto:kneeride@gmail.com">kneeride@gmail.com</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<div><span class="q">
<div>>>just look at the include files:</div>
<div> </div></span></div>
<div>
<div>i looked at the header, but got a little confused.</div>
<div>i don't see how you can call a destruct of a a memory space that still exists. ie a C version of a vector.</div>
<div> </div>
<div>shared_ptr<int> list[1024];</div>
<div>int n = 0;</div>
<div> </div>
<div>// add an item</div>
<div>shared_ptr<int> newItem(new int(1));</div>
<div>list[n++] = newItem;</div>
<div> </div>
<div>// remove the tail item</div>
<div>n--;</div>
<div>// destructor never called</div>
<div> </div>
<div>is it possible to call a destructor of an object that exists?</div>
<div>what then happens then the object goes out of scope? the destructor will be called twice.</div>
<div> </div>
<div>(or maybe i am completely missing the point)</div>
<div> </div>
<div>BTW: not sure if above code compiles (did it in my head)</div></div>
<div><span class="e" id="q_10c58bd9693f8dd4_2">
<div><br> </div>
<div><span class="gmail_quote">On 7/10/06, <b class="gmail_sendername">Boris Breidenbach</b> <<a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:Boris.Breidenbach@physik.uni-erlangen.de" target="_blank">
Boris.Breidenbach@physik.uni-erlangen.de</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">On Mon, Jul 10, 2006 at 03:58:19PM +1000, bringiton bringiton wrote:<br>> This question is based on curiosity. How does std::vector::pop_back() call
<br>> the destructor of the item getting removed?<br>><br>> i understood std::vector to be a contigious array of memory, therefore an<br>> item's memory does not go out of scope when being popped. ie the item goes
<br>> out of scope when the entire array goes out of scope.<br><br>just look at the include files:<br><br>bits/stl_vector.h says:<br>void<br> pop_back()<br> {<br> --this->_M_impl._M_finish;<br> std::_Destroy(this->_M_impl._M_finish);
<br> }<br><br>so the destructor is called in std::_Destroy. Which can be found in<br>bits/stl_construct.h:<br>/**<br> * @if maint<br> * Destroy the object pointed to by a pointer type.<br> * @endif<br> */<br>template<typename _Tp>
<br> inline void<br> _Destroy(_Tp* __pointer)<br> { __pointer->~_Tp(); }<br><br>It just calls the destructor.<br><br>_______________________________________________<br>Boost-users mailing list<br><a onclick="return top.js.OpenExtLink(window,event,this)" href="mailto:Boost-users@lists.boost.org" target="_blank">
Boost-users@lists.boost.org</a><br><a onclick="return top.js.OpenExtLink(window,event,this)" href="http://lists.boost.org/mailman/listinfo.cgi/boost-users" target="_blank">http://lists.boost.org/mailman/listinfo.cgi/boost-users
</a><br></blockquote></div><br></span></div></blockquote></div><br>