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The STL from the Inside · 3:32
Ranges and Views
C++20 lets begin and end travel together as a range, and views turn ranges into lazy pipelines. With a counter inside the test, we watch filter | take pull one element at a time: nothing runs while the pipeline is built, and 8 and 0 are never examined. Then an infinite iota pipeline that still finishes, why views are only a few bytes, and what happens when a view outlives the data it looks at.
You will learn
- Describe a range as begin/end, begin/count or begin/sentinel
- Explain laziness: a view does work only when an element is pulled
- Compare lazy pipelines with eager copies in work and memory
- Recognise dangling views and the std::ranges::dangling guard