Erase usage and return value of STL container Set,map,vector detailed parsing _c language

Summarize my experience and lessons in the work.

You can use the list, set, or map traversal to remove certain elements:

Correct use of Method 1

Copy Code code as follows:

std::list< int> list;
std::list< Int>::iterator itlist;
for (itlist = List.begin (); itlist!= list.end ();)
{
if (Willdelete (*itlist))
{
Itlist = List.erase (itlist);
}
Else
itlist++;
}

correct use of Method 2

Copy Code code as follows:

std::list< int> list;
std::list< Int>::iterator itlist;
for (itlist = List.begin (); itlist!= list.end ();)
{
if (Willdelete (*itlist))
{
List.erase (itlist++);
}
Else
itlist++;
}

Correct use of Method 3

Copy Code code as follows:

std::list< int> list;
std::list< Int>::iterator it, next;
for (it = List.begin (), next = it, next + +; it!= list.end (); it = Next, ++next)
{
if (Willdelete (*it))
{
List.erase (IT);
}
}

Note: The method three is more ingenious, but need to pay attention to method three is before use to determine whether the container is empty, otherwise the iterator will be problematic.

I test that set.erase does not return the iterator, and the list returns.
Vector delete operation

Copy Code code as follows:

Std::vector <pack_print>::iterator It;
For (It=printitems.begin (); It!=printitems.end ();)
{
I mean, how do we judge Printitems Printitems pack_print.bh =0

if (it.bh ==0)//is that so?
{//delete
It=printitems.erase (It);
}
Else
{//Do not delete
++it;
}
}

Copy Code code as follows:

Std::vector <PACK_PRINT> Printitems;
int i = 0;
while (I < printitems.size ())
{

if (printitems[i].bh = 0)//Here for example I want to printitems when pack_print.bh =0 delete how to write Yo. In addition, is it wrong to delete this?
{//delete
Printitems.erase (Printitems.begin () + i);
}
Else
{//Do not delete
++i;
}
}