Struct basic_collector< matcher< type_list< Reject... >, type_list< Require... >, Rule... >, Other... >
Synopsis
#include <src/entt/entity/observer.hpp>
template<typename... Reject, typename... Require, typename... Rule, typename... Other>
struct basic_collector<matcher<type_list<Reject...>, type_list<Require...>, Rule...>, Other...>
Description
Collector.
A collector contains a set of rules (literally, matchers) to use to track entities.
Its main purpose is to generate a descriptor that allows an observer to know how to connect to a registry.
- Template Parameters
Reject- Untracked types used to filter out entities.Require- Untracked types required by the matcher.Rule- Specific details of the current matcher.Other- Other matchers.
Methods
| group | Adds a grouping matcher to the collector. | |
| update | Adds an observing matcher to the collector. | |
| where | Updates the filter of the last added matcher. |
Source
Lines 78-115 in src/entt/entity/observer.hpp.
template<typename... Reject, typename... Require, typename... Rule, typename... Other>
struct basic_collector<matcher<type_list<Reject...>, type_list<Require...>, Rule...>, Other...> {
/*! @brief Current matcher. */
using current_type = matcher<type_list<Reject...>, type_list<Require...>, Rule...>;
/**
* @brief Adds a grouping matcher to the collector.
* @tparam AllOf Types of components tracked by the matcher.
* @tparam NoneOf Types of components used to filter out entities.
* @return The updated collector.
*/
template<typename... AllOf, typename... NoneOf>
static constexpr auto group(exclude_t<NoneOf...> = {}) ENTT_NOEXCEPT {
return basic_collector<matcher<type_list<>, type_list<>, type_list<NoneOf...>, AllOf...>, current_type, Other...>{};
}
/**
* @brief Adds an observing matcher to the collector.
* @tparam AnyOf Type of component for which changes should be detected.
* @return The updated collector.
*/
template<typename AnyOf>
static constexpr auto update() ENTT_NOEXCEPT {
return basic_collector<matcher<type_list<>, type_list<>, AnyOf>, current_type, Other...>{};
}
/**
* @brief Updates the filter of the last added matcher.
* @tparam AllOf Types of components required by the matcher.
* @tparam NoneOf Types of components used to filter out entities.
* @return The updated collector.
*/
template<typename... AllOf, typename... NoneOf>
static constexpr auto where(exclude_t<NoneOf...> = {}) ENTT_NOEXCEPT {
using extended_type = matcher<type_list<Reject..., NoneOf...>, type_list<Require..., AllOf...>, Rule...>;
return basic_collector<extended_type, Other...>{};
}
};