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The STL from the Inside · 4:38
Iterators and Algorithms
Iterators are the small shared idea that lets dozens of standard algorithms work on any container without knowing what it is. We walk "Mary had a little lamb" with half-open [begin, end) ranges and Stroustrup's find_all, climb the ladder of iterator categories (checked with the C++20 concepts on a Mac), count 20 comparisons for lower_bound against more than 600,000 for find, and see why remove never shrinks a vector.
You will learn
- Use half-open [begin, end) ranges and read end() as 'not found'
- Name the iterator categories from input to contiguous and give a container for each
- Explain why lower_bound needs random access to be fast
- Apply the erase-remove idiom and back_inserter, knowing algorithms never change a container's size