leaf.hpp

 
#ifndef UFO_CONTAINER_TREE_PREDICATE_LEAF_HPP
#define UFO_CONTAINER_TREE_PREDICATE_LEAF_HPP
 
// UFO
#include <ufo/container/tree/predicate/filter.hpp>
 
namespace ufo::pred
{
struct Leaf {
};
 
static constexpr inline Leaf const leaf;
 
template <>
struct Filter<Leaf> {
    using Pred = Leaf;
 
    template <class Tree>
    static constexpr void init(Pred&, Tree const&) noexcept
    {
    }
 
    template <class Value>
    [[nodiscard]] static constexpr bool returnableValue(Pred const&, Value const&) noexcept
    {
        return true;
    }
 
    template <class Tree>
    [[nodiscard]] static constexpr bool returnable(Pred const&, Tree const& t,
                                                   typename Tree::Node const& n) noexcept
    {
        return !t.isParent(n);
    }
 
    template <class Tree>
    [[nodiscard]] static constexpr bool traversable(Pred const&, Tree const& t,
                                                    typename Tree::Node const& n) noexcept
    {
        return true;
    }
 
    template <class Tree>
    [[nodiscard]] static constexpr bool returnableRay(Pred const& p, Tree const& t,
                                                      typename Tree::Node const& n,
                                                      typename Tree::Ray const&) noexcept
    {
        return returnable(p, t, n);
    }
 
    template <class Tree>
    [[nodiscard]] static constexpr bool traversableRay(Pred const& p, Tree const& t,
                                                       typename Tree::Node const& n,
                                                       typename Tree::Ray const&) noexcept
    {
        return traversable(p, t, n);
    }
};
}  // namespace ufo::pred
 
#endif  // UFO_CONTAINER_TREE_PREDICATE_LEAF_HPP