Class entt_traits
Synopsis
#include <src/entt/entity/entity.hpp>
template<typename Type>
class entt_traits: internal::entt_traits<Type>
Description
Entity traits.
- Template Parameters
Type- Type of identifier.
Inheritance
Ancestors: internal::entt_traits< Type >
Methods
| combine | Combines two identifiers in a single one. | |
| construct | Constructs an identifier from its parts. | |
| to_entity | Returns the entity part once converted to the underlying type. | |
| to_integral | Converts an entity to its underlying type. | |
| to_version | Returns the version part once converted to the underlying type. |
Source
Lines 61-132 in src/entt/entity/entity.hpp.
template<typename Type>
class entt_traits: internal::entt_traits<Type> {
using base_type = internal::entt_traits<Type>;
public:
/*! @brief Value type. */
using value_type = Type;
/*! @brief Underlying entity type. */
using entity_type = typename base_type::entity_type;
/*! @brief Underlying version type. */
using version_type = typename base_type::version_type;
/*! @brief Reserved identifier. */
static constexpr entity_type reserved = base_type::entity_mask | (base_type::version_mask << base_type::entity_shift);
/*! @brief Page size, default is `ENTT_SPARSE_PAGE`. */
static constexpr auto page_size = ENTT_SPARSE_PAGE;
/**
* @brief Converts an entity to its underlying type.
* @param value The value to convert.
* @return The integral representation of the given value.
*/
[[nodiscard]] static constexpr entity_type to_integral(const value_type value) ENTT_NOEXCEPT {
return static_cast<entity_type>(value);
}
/**
* @brief Returns the entity part once converted to the underlying type.
* @param value The value to convert.
* @return The integral representation of the entity part.
*/
[[nodiscard]] static constexpr entity_type to_entity(const value_type value) ENTT_NOEXCEPT {
return (to_integral(value) & base_type::entity_mask);
}
/**
* @brief Returns the version part once converted to the underlying type.
* @param value The value to convert.
* @return The integral representation of the version part.
*/
[[nodiscard]] static constexpr version_type to_version(const value_type value) ENTT_NOEXCEPT {
return (to_integral(value) >> base_type::entity_shift);
}
/**
* @brief Constructs an identifier from its parts.
*
* If the version part is not provided, a tombstone is returned.<br/>
* If the entity part is not provided, a null identifier is returned.
*
* @param entity The entity part of the identifier.
* @param version The version part of the identifier.
* @return A properly constructed identifier.
*/
[[nodiscard]] static constexpr value_type construct(const entity_type entity, const version_type version) ENTT_NOEXCEPT {
return value_type{(entity & base_type::entity_mask) | (static_cast<entity_type>(version) << base_type::entity_shift)};
}
/**
* @brief Combines two identifiers in a single one.
*
* The returned identifier is a copy of the first element except for its
* version, which is taken from the second element.
*
* @param lhs The identifier from which to take the entity part.
* @param rhs The identifier from which to take the version part.
* @return A properly constructed identifier.
*/
[[nodiscard]] static constexpr value_type combine(const entity_type lhs, const entity_type rhs) ENTT_NOEXCEPT {
constexpr auto mask = (base_type::version_mask << base_type::entity_shift);
return value_type{(lhs & base_type::entity_mask) | (rhs & mask)};
}
};