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Templates and Generic Programming · 4:09
Concepts
C++20 concepts let a template say in plain words what it needs from its types. We compare a 188-line std::sort error with a one-line ranges::sort error, write a Number concept with a requires expression, see the compiler stop a bad call at the doorway, and watch the most constrained overload of advance() pick a one-hop jump for vectors and ten steps for lists.
You will learn
- Explain what a concept is: a yes/no question about a type, answered at compile time
- Write a concept with a requires expression and use it as Number auto
- Read a concept failure message and see why it beats an old template error
- Predict which constrained overload runs: the most constrained match wins