ClickHouse/src/Functions/castTypeToEither.h

#pragma once

#include <Common/typeid_cast.h>
#include <base/TypeList.h>

namespace DB
{
template <typename... Ts, typename T, typename F>
static bool castTypeToEither(const T * type, F && f)
{
    /// XXX can't use && here because gcc-7 complains about parentheses around && within ||
    return ((typeid_cast<const Ts *>(type) ? f(*typeid_cast<const Ts *>(type)) : false) || ...);
}

template <class ...Args>
constexpr bool castTypeToEither(TypeList<Args...>, const auto * type, auto && f)
{
    return (
        (typeid_cast<const Args *>(type) != nullptr
            ? std::forward<decltype(f)>(f)(
                *typeid_cast<const Args *>(type))
            : false)
        || ...);
}
}