#include <iostream>
#include <cstdint>

using s8 = std::int8_t;
using u8 = std::uint8_t;

using s16 = std::int16_t;
using u16 = std::uint16_t;

using s32 = std::int32_t;
using u32 = std::uint32_t;

using s64 = std::int64_t;
using u64 = std::uint64_t;

using namespace std;

template <typename TIndex>
struct CVertexManagerFixed
{
    template <typename TPathBuilder, typename TCompoundVertex>
    class CDataStorage : public TPathBuilder::template CDataStorage<TCompoundVertex>
    {
    public:
        using CDataStorageBase = typename TPathBuilder::template CDataStorage<TCompoundVertex>;
        using Vertex = TCompoundVertex;
        using Index = TIndex;

    public:
        inline CDataStorage(const u32 vertex_count);
        inline virtual ~CDataStorage();
        inline Vertex& get_node(const Index& vertex_id) const;
    };
};


#define TEMPLATE_SPECIALIZATION                           \
    template <typename TIndex> \
    template <typename TPathBuilder, typename TCompoundVertex>

#define CFixedVertexManager \
    CVertexManagerFixed<TIndex>::template CDataStorage<TPathBuilder, TCompoundVertex> //  error#1: non-template ‘CDataStorage’ used as template  error#2: expected unqualified-id before ‘,’ token

TEMPLATE_SPECIALIZATION
inline CFixedVertexManager::CDataStorage(const u32 vertex_count)
    : CDataStorageBase(vertex_count)
{
}

TEMPLATE_SPECIALIZATION
inline typename CFixedVertexManager::Vertex& CFixedVertexManager::get_node(const Index& vertex_id) const
{
    VERIFY(vertex_id < m_max_node_count);
    VERIFY(is_visited(vertex_id));
    return *m_indexes[vertex_id].m_vertex;
}