CPP20

https://github.com/Cpp-Club/Cxx_HOPL4_zh

coroutine

• https://en.wikipedia.org/wiki/Coroutine
• https://stackoverflow.com/questions/43503656/what-are-coroutines-in-c20

templated lambda

• Can lambda functions be templated?

std::identity

• https://en.cppreference.com/w/cpp/utility/functional/identity

• https://en.cppreference.com/w/cpp/types/type_identity

• When to use the "identity" tmp trick?

• C++雾中风景17:模板的非推断语境与std::type_identity