Intermediate C++ Game Programming Tutorial 15
Iterators are just fancy pointers for containers. In this video we learn how to use iterators, what they're good for, and we go through all this trouble in the first place (answer: because they enable some pretty sweet shit).
Contents
Topics Covered
- Iterator operations (increment/decrement, dereference, add/sub, etc.)
- Getting iterators from containers (begin/end)
- Sequence ranges [closed,open)
- Container manipulation functions (erase/insert)
- Iterators and template algorithms (generic algorithms)
- Iterator types (random access/bidirectional/forward etc.)
- const_iterator (cbegin/cend) & reverse iterators (rbegin/rend)
- Free iterator functions (std::begin/end/advance/next/prev)
- Iterator adapters (back_inserter, ostream_iterator)
Video Timestamp Index
Answer to erase puzzle
The reason why we do not increment the iterator i in the for loop, but instead increment it conditionally in the body of the loop is, if we erase an element, the returned iterator will point to the next element after the erased one, and if we were incrementing every iteration of the loop, it would skip all elements that immediately follow an erased element. Instead, we only increment if we did not erase an element, and this ensures that all elements are tested.
Homework
Modify our linked list stack to work with range based for loops. You are not allowed to modify any code outsize of the Stack class. If you want an extra challenge after completing Level 1, you can uncomment the code for Level 2 and try to get it to compile as well.
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