osrm-backend/include/util/graph_traits.hpp
2022-12-20 18:00:11 +01:00

50 lines
1.2 KiB
C++

#ifndef OSRM_GRAPH_TRAITS_HPP
#define OSRM_GRAPH_TRAITS_HPP
#include <type_traits>
namespace osrm::util::traits
{
// Introspection for an arbitrary .data member attribute
template <typename T, typename = void> struct HasDataMember : std::false_type
{
};
template <typename T>
struct HasDataMember<T, decltype((void)(sizeof(std::declval<T>().data) > 0))> : std::true_type
{
};
// Introspection for an arbitrary .target member attribute
template <typename T, typename = void> struct HasTargetMember : std::false_type
{
};
template <typename T>
struct HasTargetMember<T, decltype((void)(sizeof(std::declval<T>().target) > 0))> : std::true_type
{
};
// Our graphs require edges to have a .target and .data member attribute
template <typename Edge>
struct HasDataAndTargetMember
: std::integral_constant<bool, HasDataMember<Edge>::value && HasTargetMember<Edge>::value>
{
};
// Our graphs require nodes to have a .first_edge member attribute
template <typename T, typename = void> struct HasFirstEdgeMember : std::false_type
{
};
template <typename T>
struct HasFirstEdgeMember<T, decltype((void)(sizeof(std::declval<T>().first_edge) > 0))>
: std::true_type
{
};
} // namespace osrm::util::traits
#endif // STATIC_GRAPH_TRAITS_HPP