for_each.hpp

// Copyright (C) The DDC development team, see COPYRIGHT.md file
//
// SPDX-License-Identifier: MIT
 
#pragma once
 
#include <array>
#include <cstddef>
#include <utility>
 
#include "ddc/discrete_domain.hpp"
#include "ddc/discrete_element.hpp"
#include "ddc/discrete_vector.hpp"
 
namespace ddc {
 
namespace detail {
 
template <class RetType, class Element, std::size_t N, class Functor, class... Is>
void for_each_serial(
        std::array<Element, N> const& begin,
        std::array<Element, N> const& end,
        Functor const& f,
        Is const&... is) noexcept
{
    static constexpr std::size_t I = sizeof...(Is);
    if constexpr (I == N) {
        f(RetType(is...));
    } else {
        for (Element ii = begin[I]; ii < end[I]; ++ii) {
            for_each_serial<RetType>(begin, end, f, is..., ii);
        }
    }
}
 
} // namespace detail
 
/** iterates over a nD domain in serial
 * @param[in] domain the domain over which to iterate
 * @param[in] f      a functor taking an index as parameter
 */
template <class... DDims, class Functor>
void for_each(DiscreteDomain<DDims...> const& domain, Functor&& f) noexcept
{
    DiscreteElement<DDims...> const ddc_begin = domain.front();
    DiscreteElement<DDims...> const ddc_end = domain.front() + domain.extents();
    std::array const begin = detail::array(ddc_begin);
    std::array const end = detail::array(ddc_end);
    detail::for_each_serial<DiscreteElement<DDims...>>(begin, end, std::forward<Functor>(f));
}
 
} // namespace ddc