Re: Deleting items from an std::list , is this code correct?
Ramon: my bad, I mistyped iostream for conio
Victor: The idea of the code is to ask if it is possible to store
iterators and later use them.
Juha: looks nice, I didn't notice that erase returns another iterator
beyond the one that is just deleted!
I haven't tried it, but theoretically, this shouldn't work, no?
void delete_odd(int_list_t &L)
{
int_list_iterator_list_t it_list;
for (int_list_t::iterator it=L.begin();it!=L.end();++it)
{
if (*it % 2 != 0)
it_list.push_back(it);
}
for (int_list_iterator_list_t::const_iterator
di=it_list.begin();di!
=it_list.end();++di)
{
L.erase(*di);
}
}
I only moved the declaration of "it" to inside the loop, that should
free the iterator by the end of the loop, thus rendering all the
stored iterators in it_list unusable?
Regards,
Elias
On Apr 24, 1:18 am, Ramon F Herrera <ra...@conexus.net> wrote:
On Apr 23, 3:21 pm,lallous<lall...@lgwm.org> wrote:
#include <conio>
#include <list>
typedef std::list<int> int_list_t;
typedef std::list<int_list_t::iterator> int_list_iterator_list_t;
void print_list(int_list_t &L)
{
for (int_list_t::iterator it=L.begin();it!=L.end();++it)
{
std::cout << "value = " << *it << std::endl;
}
}
void delete_odd(int_list_t &L)
{
int_list_iterator_list_t it_list;
int_list_t::iterator it;
for (it=L.begin();it!=L.end();++it)
{
if (*it % 2 != 0)
it_list.push_back(it);
}
for (int_list_iterator_list_t::const_iterator di=it_list.begin();di!
=it_list.end();++di)
{
L.erase(*di);
}
}
void populate_list(int_list_t &L, int start, int end)
{
L.clear();
for (int i=start;i<=end;i++)
L.push_back(i);
}
int main()
{
int_list_t L;
populate_list(L, 1, 10);
print_list(L);
std::cout << "---------------------" << std::endl;
delete_odd(L);
print_list(L);
return 0;
}
Please advise. Does this work with all STL implementations?
Thank you,
Elias
After making a minor modification, your code runs properly under MSVS
ang gcc.
I changed the line:
#include <conio>
to
#include <iostream>
-RFH