Removing elements from vector

I cannot relieve that I am working on Thanksgiving, but I am stuck over
something that should be simple. I have a vector that has twenty-four
elements. I need to remove the four elements whose positions equal
zero. The code below only removes two of the four. Any ideas?
>
logfile << "\n\n\n. . .removing flat positions";
logfile << "vector size=" << componentPerformance.size() << endl;
>
>
int position=0;
for (vector<cPerformance>::iterator itr =
componentPerformance.begin();itr!=componentPerform ance.end(); ++itr)
{
position=itr->returnPosition(); //returnPosition() returns a float
logfile << endl << itr->returnSymbol() << "Position=" <<
itr->returnPosition();
if(position==0)
{
logfile << "\tremoving. . . " << itr->returnSymbol();
componentPerformance.erase(itr);
}
}
>
logfile.close();

Use typedefs!
>
if cPerformance is cheep to copy:
>
typedef ::std::vector<cPerformance container_t;
container_t tmp;
::std::remove_copy_if(componentPerformance.begin() ,componentPerformance.end(),
::std::back_inserter(tmp),
!::boost::bind(::std::not_equal_to<int>(),
::boost::bind(&cPerformance:: returnPosition, _1), 0));
>
componentPerformance.swap(tmp);

for(container_t::iterator it = componentPerformance.begin();
it != componentPerformance.end(); ++it)
{
if((*it). returnPosition() == 0)
it = componentPerformance.erase(it);
}

dasjotre wrote:>
No wonder nobody outside C++ ghetto considers C++ to be language
suitable to do any real work anymore :)

>
I believe this code is wrong - it skips elements past removed one.

Mirek Fidler wrote:
>>
A call for a simpler example !
>
inline bool operator == (cPerformance const & l, cPerformance const &
r)
{
return l.returnPosition() == r.returnPosition();
}
>
cPerformance nulperf(0);
>
::std::remove_copy(componentPerformance.begin(),co mponentPerformance.end(),
::std::back_inserter(tmp), nulperf);
componentPerformance.swap(tmp);
>
Which one would teach you more?
> { continue;
}>
Not any more ;)

container_t::iterator it = componentPerformance.begin();
while(it != componentPerformance.end())
{
if((*it).returnPosition() == 0)
it = componentPerformance.erase(it);
else
++it;
}
>
Good example to argue against hand coded loops

>
Good example to teach you check twice before hitting Post button ;)
>

I cannot relieve that I am working on Thanksgiving, but I am stuck over
something that should be simple. I have a vector that has twenty-four
elements. I need to remove the four elements whose positions equal
zero. The code below only removes two of the four. Any ideas?

I cannot relieve that I am working on Thanksgiving, but I am stuck over
something that should be simple. I have a vector that has twenty-four
elements. I need to remove the four elements whose positions equal
zero. The code below only removes two of the four. Any ideas?
>
logfile << "\n\n\n. . .removing flat positions";
logfile << "vector size=" << componentPerformance.size() << endl;
>
>
int position=0;
for (vector<cPerformance>::iterator itr =
componentPerformance.begin();itr!=componentPerform ance.end(); ++itr)
{
position=itr->returnPosition(); //returnPosition() returns a float
logfile << endl << itr->returnSymbol() << "Position=" <<
itr->returnPosition();
if(position==0)
{
logfile << "\tremoving. . . " << itr->returnSymbol();
componentPerformance.erase(itr);
}
}
>
logfile.close();

{
logfile << "\tremoving. . . " << itr->returnSymbol();
componentPerformance.erase(itr);
--itr; // because itr points to the next element.
}

I cannot relieve that I am working on Thanksgiving, but I am stuck over
something that should be simple. I have a vector that has twenty-four
elements. I need to remove the four elements whose positions equal
zero. The code below only removes two of the four. Any ideas?
>
logfile << "\n\n\n. . .removing flat positions";
logfile << "vector size=" << componentPerformance.size() << endl;
>
>
int position=0;
for (vector<cPerformance>::iterator itr =
componentPerformance.begin();itr!=componentPerform ance.end(); ++itr)
{
position=itr->returnPosition(); //returnPosition() returns a float
logfile << endl << itr->returnSymbol() << "Position=" <<
itr->returnPosition();
if(position==0)
{
logfile << "\tremoving. . . " << itr->returnSymbol();
componentPerformance.erase(itr);
}
}
>
logfile.close();