Using C++20's Three-way Comparison ＜=＞
summary
C++20's three-way comparison (<=>) lets classes delegate comparison logic to the compiler by writing a defaulted <=>, which yields lexicographic member-wise ordering and auto-generates == and relational operators to eliminate boilerplate. It introduces the comparison category types strong_ordering, weak_ordering, and partial_ordering, defines operator-rewriting rules for templates and containers, and discusses pitfalls such as floating-point partial orders, implicit conversions, and heterogeneous comparison overload resolution.
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chapters (8)
- 0:00Introduction to C++20 comparison
- 7:31Default comparison operators
- 15:01Member function comparison
- 22:22Spaceship operator use cases
- 33:39Library and container support
- 40:45Global comparison operator
- 45:28Optional and custom comparison
- 51:33Summary and Q&A
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