rpcs3/Utilities/variant_visitor.hpp

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#ifndef MAPBOX_UTIL_VARIANT_VISITOR_HPP
#define MAPBOX_UTIL_VARIANT_VISITOR_HPP
#include <utility>
//namespace mapbox {
//namespace util {
namespace std {
template <typename... Fns>
struct visitor;
template <typename Fn>
struct visitor<Fn> : Fn
{
using Fn::operator();
template<typename T>
visitor(T&& fn) : Fn(std::forward<T>(fn)) {}
};
template <typename Fn, typename... Fns>
struct visitor<Fn, Fns...> : Fn, visitor<Fns...>
{
using Fn::operator();
using visitor<Fns...>::operator();
template<typename T, typename... Ts>
visitor(T&& fn, Ts&&... fns)
: Fn(std::forward<T>(fn))
, visitor<Fns...>(std::forward<Ts>(fns)...) {}
};
template <typename... Fns>
visitor<typename std::decay<Fns>::type...> make_visitor(Fns&&... fns)
{
return visitor<typename std::decay<Fns>::type...>
(std::forward<Fns>(fns)...);
}
}
//} // namespace util
//} // namespace mapbox
#endif // MAPBOX_UTIL_VARIANT_VISITOR_HPP