for_each.hpp

#pragma once
 
namespace ossia
{
// Invokes the functor with every type
 
template <typename T>
struct type_tag
{
  using type = T;
};
 
template <template <typename...> typename T, typename... Args, typename F>
constexpr void for_each(T<Args...>, F f)
{
  (f.template operator()<Args>(), ...);
}
 
template <template <typename...> typename T, typename... Args, typename F>
constexpr void for_each_tagged(T<Args...>, F f)
{
  (f(type_tag<Args>{}), ...);
}
 
template <typename... Args, typename F>
constexpr void for_each_type(F f)
{
  (f.template operator()<Args>(), ...);
}
 
template <template <typename...> typename T, typename... Args, typename F>
constexpr void for_each_type(T<Args...>, F f)
{
  (f.template operator()<Args>(), ...);
}
 
template <typename... Args, typename F>
constexpr void for_each_type_tagged(F f)
{
  (f(type_tag<Args>{}), ...);
}
 
// Invokes the functor with every type, this code generation is done at compile
// time
template <typename... Args, typename F>
constexpr void for_each_type_if(F&& f)
{
  (f.template operator()<Args>() || ...);
}
 
template <typename... Args, typename F>
constexpr void for_each_type_if_tagged(F&& f)
{
  (f(type_tag<Args>{}) || ...);
}
}