Type Traits

TooManyCooks offers some concepts / type traits in the tmc::traits namespace, accessible by including tmc/traits.hpp. There are two groups of traits.

First, traits to let you work with values/awaitables/packaged tasks:

• if a type is awaitable or not

• if awaitable, what is the result type

• if a type is non-awaitable callable with no arguments

• if non-awaitable callable with no arguments, what is the return type

• (combining the above) the result of awaiting or calling a type

Example usage - a generic handler that can accept any value, awaitable, or packaged task:

template <typename T>
void handler(T&& t) {
  if constexpr (tmc::traits::is_awaitable<T>) {
    process(co_await std::forward<T>(t));
  } else if constexpr (tmc::traits::is_callable<T>) {
    process(std::forward<T>(t)());
  } else {
    process(std::forward<T>(t));
  }
}

Secondly, traits to let you work with tmc::task and functors:

• if a type is a task

• if a type is a void-returning or non-void-returning task

• if a type is a non-task functor

• if a type is a void-returning or non-void-returning non-task functor

For full info, see the documentation inline at: tmc/traits.hpp