Delete list element using element pointer - c++

Question

I'd like to create a method that takes two arguments: List of string and pointer to list element. Next, I would like to delete the list item pointed to by the pointer.
Firstly i create simple list:
list<string> list_ptr = { "1", "2", "3", "4", "5", "6", "7", "8"};
I suppose that i first should check element exist:
auto it = find(list_ptr.begin(), list_ptr.end(), "4");
And if element exist, get his pointer and call function delete:
void delete(node_t *list_ptr, node_t *p)
My problem is that I have no idea if it is even possible to delete a list item using its pointer. Additionally, how can I get the indicator of a single list item?
Yes, I am C++ newbie :)

Answer 1

std::list has its own interface for deleting, sorting, etc:
#include <stdio.h>
#include <list>
#include <string>
int main() {
std::list<std::string> strlist = {"1", "2", "3", "4", "5", "6", "7", "8"};
strlist.remove("4");
for (auto const& elm : strlist) puts(elm.c_str());
}
If you want to use the iterators like in your example, here's how you do it:
std::list<std::string> strlist = {"1", "2", "3", "4", "5", "6", "7", "8"};
auto it = std::find(strlist.begin(), strlist.end(), "4");
if (it != strlist.end()) strlist.erase(it);
On that note, if preserving the ordering is not a concern for you, you can have efficient O(1) removal from anywhere in std::vector, which is generally a better containier:
#include <stdio.h>
#include <algorithm>
#include <iterator>
#include <string>
#include <vector>
int main() {
std::vector<std::string> strvec = {"1", "2", "3", "4", "5", "6", "7", "8"};
auto it = std::find(strvec.begin(), strvec.end(), "4");
if (it != strvec.end()) {
std::iter_swap(it, std::prev(strvec.end()));
strvec.pop_back();
}
for (auto const& elm : strvec) puts(elm.c_str());
}