location_set.h

// Description: A set with a locator; a point-set.
// Documentation: pointset.txt

#ifndef PASTELSYS_LOCATION_SET_H
#define PASTELSYS_LOCATION_SET_H

#include "pastel/sys/set/set_concept.h"
#include "pastel/sys/set/transformed_set.h"
#include "pastel/sys/locator/locator_concept.h"
#include "pastel/sys/locator/location.h"

#include <range/v3/all.hpp>

namespace Pastel
{

    using Assignable_Concept = ranges::concepts::Assignable;

    //! A set with a locator; a point-set.
    template <
        typename Set,
        typename Locator,
        typename Base>
    class LocationSet
    : public Base
    {
    public:
        using Index = Set_Index<std::add_const_t<Set>>;

        PASTEL_CONCEPT_CHECK(Set, Set_Concept);
        PASTEL_CONCEPT_CHECK(Locator, Locator_Concept);

        LocationSet(
            const Set& set,
            const Locator& locator,
            const Base& base)
            : Base(base)
            , set_(set)
            , locator_(locator)
        {
        }

        const Set& pointSetSet() const
        {
            return set_;
        }

        const Locator& pointSetLocator() const
        {
            return locator_;
        }

    private:
        const Set& set_;
        Locator locator_;
    };

    template <typename Type>
    struct IsLocationSet
        : std::false_type
    {};

    template <
        typename Set, 
        typename Locator,
        typename Base>
    struct IsLocationSet<LocationSet<Set, Locator, Base>>
        : std::true_type
    {};

    //! Constructs a location-set from a point-set and a locator.
    template <
        typename Set, 
        typename Locator,
        Requires<
            Models<Set, Set_Concept>,
            Models<Locator, Locator_Concept>
        > = 0
    >
    decltype(auto) locationSet(
        const Set& set,
        const Locator& locator)
    {
        auto transformedSet_ = transformedSet(
            set,
            [=](auto&& element){return location(element, locator);});

        using Base = decltype(transformedSet_);

        return LocationSet<Set, Locator, Base>(set, locator, transformedSet_);
    }

}

#endif