LiteLoaderBDS-1.16.40/LiteLoader/third-party/include/entt/signal/sigh.hpp
2023-03-01 23:21:09 -08:00

565 lines
18 KiB
C++

#ifndef ENTT_SIGNAL_SIGH_HPP
#define ENTT_SIGNAL_SIGH_HPP
#include <algorithm>
#include <functional>
#include <type_traits>
#include <utility>
#include <vector>
#include "delegate.hpp"
#include "fwd.hpp"
namespace entt {
/**
* @brief Sink class.
*
* Primary template isn't defined on purpose. All the specializations give a
* compile-time error unless the template parameter is a function type.
*
* @tparam Type A valid signal handler type.
*/
template<typename Type>
class sink;
/**
* @brief Unmanaged signal handler.
*
* Primary template isn't defined on purpose. All the specializations give a
* compile-time error unless the template parameter is a function type.
*
* @tparam Type A valid function type.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Type, typename Allocator>
class sigh;
/**
* @brief Unmanaged signal handler.
*
* It works directly with references to classes and pointers to member functions
* as well as pointers to free functions. Users of this class are in charge of
* disconnecting instances before deleting them.
*
* This class serves mainly two purposes:
*
* * Creating signals to use later to notify a bunch of listeners.
* * Collecting results from a set of functions like in a voting system.
*
* @tparam Ret Return type of a function type.
* @tparam Args Types of arguments of a function type.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Ret, typename... Args, typename Allocator>
class sigh<Ret(Args...), Allocator> {
/*! @brief A sink is allowed to modify a signal. */
friend class sink<sigh<Ret(Args...), Allocator>>;
using alloc_traits = std::allocator_traits<Allocator>;
using container_type = std::vector<delegate<Ret(Args...)>, typename alloc_traits::template rebind_alloc<delegate<Ret(Args...)>>>;
public:
/*! @brief Allocator type. */
using allocator_type = Allocator;
/*! @brief Unsigned integer type. */
using size_type = std::size_t;
/*! @brief Sink type. */
using sink_type = sink<sigh<Ret(Args...), Allocator>>;
/*! @brief Default constructor. */
sigh() noexcept(std::is_nothrow_default_constructible_v<allocator_type> &&std::is_nothrow_constructible_v<container_type, const allocator_type &>)
: sigh{allocator_type{}} {}
/**
* @brief Constructs a signal handler with a given allocator.
* @param allocator The allocator to use.
*/
explicit sigh(const allocator_type &allocator) noexcept(std::is_nothrow_constructible_v<container_type, const allocator_type &>)
: calls{allocator} {}
/**
* @brief Copy constructor.
* @param other The instance to copy from.
*/
sigh(const sigh &other) noexcept(std::is_nothrow_copy_constructible_v<container_type>)
: calls{other.calls} {}
/**
* @brief Allocator-extended copy constructor.
* @param other The instance to copy from.
* @param allocator The allocator to use.
*/
sigh(const sigh &other, const allocator_type &allocator) noexcept(std::is_nothrow_constructible_v<container_type, const container_type &, const allocator_type &>)
: calls{other.calls, allocator} {}
/**
* @brief Move constructor.
* @param other The instance to move from.
*/
sigh(sigh &&other) noexcept(std::is_nothrow_move_constructible_v<container_type>)
: calls{std::move(other.calls)} {}
/**
* @brief Allocator-extended move constructor.
* @param other The instance to move from.
* @param allocator The allocator to use.
*/
sigh(sigh &&other, const allocator_type &allocator) noexcept(std::is_nothrow_constructible_v<container_type, container_type &&, const allocator_type &>)
: calls{std::move(other.calls), allocator} {}
/**
* @brief Copy assignment operator.
* @param other The instance to copy from.
* @return This signal handler.
*/
sigh &operator=(const sigh &other) noexcept(std::is_nothrow_copy_assignable_v<container_type>) {
calls = other.calls;
return *this;
}
/**
* @brief Move assignment operator.
* @param other The instance to move from.
* @return This signal handler.
*/
sigh &operator=(sigh &&other) noexcept(std::is_nothrow_move_assignable_v<container_type>) {
calls = std::move(other.calls);
return *this;
}
/**
* @brief Exchanges the contents with those of a given signal handler.
* @param other Signal handler to exchange the content with.
*/
void swap(sigh &other) noexcept(std::is_nothrow_swappable_v<container_type>) {
using std::swap;
swap(calls, other.calls);
}
/**
* @brief Returns the associated allocator.
* @return The associated allocator.
*/
[[nodiscard]] constexpr allocator_type get_allocator() const noexcept {
return calls.get_allocator();
}
/**
* @brief Number of listeners connected to the signal.
* @return Number of listeners currently connected.
*/
[[nodiscard]] size_type size() const noexcept {
return calls.size();
}
/**
* @brief Returns false if at least a listener is connected to the signal.
* @return True if the signal has no listeners connected, false otherwise.
*/
[[nodiscard]] bool empty() const noexcept {
return calls.empty();
}
/**
* @brief Triggers a signal.
*
* All the listeners are notified. Order isn't guaranteed.
*
* @param args Arguments to use to invoke listeners.
*/
void publish(Args... args) const {
for(auto &&call: std::as_const(calls)) {
call(args...);
}
}
/**
* @brief Collects return values from the listeners.
*
* The collector must expose a call operator with the following properties:
*
* * The return type is either `void` or such that it's convertible to
* `bool`. In the second case, a true value will stop the iteration.
* * The list of parameters is empty if `Ret` is `void`, otherwise it
* contains a single element such that `Ret` is convertible to it.
*
* @tparam Func Type of collector to use, if any.
* @param func A valid function object.
* @param args Arguments to use to invoke listeners.
*/
template<typename Func>
void collect(Func func, Args... args) const {
for(auto &&call: calls) {
if constexpr(std::is_void_v<Ret>) {
if constexpr(std::is_invocable_r_v<bool, Func>) {
call(args...);
if(func()) {
break;
}
} else {
call(args...);
func();
}
} else {
if constexpr(std::is_invocable_r_v<bool, Func, Ret>) {
if(func(call(args...))) {
break;
}
} else {
func(call(args...));
}
}
}
}
private:
container_type calls;
};
/**
* @brief Connection class.
*
* Opaque object the aim of which is to allow users to release an already
* estabilished connection without having to keep a reference to the signal or
* the sink that generated it.
*/
class connection {
/*! @brief A sink is allowed to create connection objects. */
template<typename>
friend class sink;
connection(delegate<void(void *)> fn, void *ref)
: disconnect{fn}, signal{ref} {}
public:
/*! @brief Default constructor. */
connection()
: disconnect{},
signal{} {}
/**
* @brief Checks whether a connection is properly initialized.
* @return True if the connection is properly initialized, false otherwise.
*/
[[nodiscard]] explicit operator bool() const noexcept {
return static_cast<bool>(disconnect);
}
/*! @brief Breaks the connection. */
void release() {
if(disconnect) {
disconnect(signal);
disconnect.reset();
}
}
private:
delegate<void(void *)> disconnect;
void *signal;
};
/**
* @brief Scoped connection class.
*
* Opaque object the aim of which is to allow users to release an already
* estabilished connection without having to keep a reference to the signal or
* the sink that generated it.<br/>
* A scoped connection automatically breaks the link between the two objects
* when it goes out of scope.
*/
struct scoped_connection {
/*! @brief Default constructor. */
scoped_connection() = default;
/**
* @brief Constructs a scoped connection from a basic connection.
* @param other A valid connection object.
*/
scoped_connection(const connection &other)
: conn{other} {}
/*! @brief Default copy constructor, deleted on purpose. */
scoped_connection(const scoped_connection &) = delete;
/**
* @brief Move constructor.
* @param other The scoped connection to move from.
*/
scoped_connection(scoped_connection &&other) noexcept
: conn{std::exchange(other.conn, {})} {}
/*! @brief Automatically breaks the link on destruction. */
~scoped_connection() {
conn.release();
}
/**
* @brief Default copy assignment operator, deleted on purpose.
* @return This scoped connection.
*/
scoped_connection &operator=(const scoped_connection &) = delete;
/**
* @brief Move assignment operator.
* @param other The scoped connection to move from.
* @return This scoped connection.
*/
scoped_connection &operator=(scoped_connection &&other) noexcept {
conn = std::exchange(other.conn, {});
return *this;
}
/**
* @brief Acquires a connection.
* @param other The connection object to acquire.
* @return This scoped connection.
*/
scoped_connection &operator=(connection other) {
conn = std::move(other);
return *this;
}
/**
* @brief Checks whether a scoped connection is properly initialized.
* @return True if the connection is properly initialized, false otherwise.
*/
[[nodiscard]] explicit operator bool() const noexcept {
return static_cast<bool>(conn);
}
/*! @brief Breaks the connection. */
void release() {
conn.release();
}
private:
connection conn;
};
/**
* @brief Sink class.
*
* A sink is used to connect listeners to signals and to disconnect them.<br/>
* The function type for a listener is the one of the signal to which it
* belongs.
*
* The clear separation between a signal and a sink permits to store the former
* as private data member without exposing the publish functionality to the
* users of the class.
*
* @warning
* Lifetime of a sink must not overcome that of the signal to which it refers.
* In any other case, attempting to use a sink results in undefined behavior.
*
* @tparam Ret Return type of a function type.
* @tparam Args Types of arguments of a function type.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Ret, typename... Args, typename Allocator>
class sink<sigh<Ret(Args...), Allocator>> {
using signal_type = sigh<Ret(Args...), Allocator>;
using difference_type = typename signal_type::container_type::difference_type;
template<auto Candidate, typename Type>
static void release(Type value_or_instance, void *signal) {
sink{*static_cast<signal_type *>(signal)}.disconnect<Candidate>(value_or_instance);
}
template<auto Candidate>
static void release(void *signal) {
sink{*static_cast<signal_type *>(signal)}.disconnect<Candidate>();
}
auto before(delegate<Ret(Args...)> call) {
const auto &calls = signal->calls;
const auto it = std::find(calls.cbegin(), calls.cend(), std::move(call));
sink other{*this};
other.offset = calls.cend() - it;
return other;
}
public:
/**
* @brief Constructs a sink that is allowed to modify a given signal.
* @param ref A valid reference to a signal object.
*/
sink(sigh<Ret(Args...), Allocator> &ref) noexcept
: offset{},
signal{&ref} {}
/**
* @brief Returns false if at least a listener is connected to the sink.
* @return True if the sink has no listeners connected, false otherwise.
*/
[[nodiscard]] bool empty() const noexcept {
return signal->calls.empty();
}
/**
* @brief Returns a sink that connects before a given free function or an
* unbound member.
* @tparam Function A valid free function pointer.
* @return A properly initialized sink object.
*/
template<auto Function>
[[nodiscard]] sink before() {
delegate<Ret(Args...)> call{};
call.template connect<Function>();
return before(std::move(call));
}
/**
* @brief Returns a sink that connects before a free function with payload
* or a bound member.
* @tparam Candidate Member or free function to look for.
* @tparam Type Type of class or type of payload.
* @param value_or_instance A valid object that fits the purpose.
* @return A properly initialized sink object.
*/
template<auto Candidate, typename Type>
[[nodiscard]] sink before(Type &&value_or_instance) {
delegate<Ret(Args...)> call{};
call.template connect<Candidate>(value_or_instance);
return before(std::move(call));
}
/**
* @brief Returns a sink that connects before a given instance or specific
* payload.
* @tparam Type Type of class or type of payload.
* @param value_or_instance A valid object that fits the purpose.
* @return A properly initialized sink object.
*/
template<typename Type, typename = std::enable_if_t<!std::is_same_v<std::decay_t<std::remove_pointer_t<Type>>, void>, sink>>
[[nodiscard]] sink before(Type &value_or_instance) {
return before(&value_or_instance);
}
/**
* @brief Returns a sink that connects before a given instance or specific
* payload.
* @param value_or_instance A valid pointer that fits the purpose.
* @return A properly initialized sink object.
*/
[[nodiscard]] sink before(const void *value_or_instance) {
sink other{*this};
if(value_or_instance) {
const auto &calls = signal->calls;
const auto it = std::find_if(calls.cbegin(), calls.cend(), [value_or_instance](const auto &delegate) {
return delegate.data() == value_or_instance;
});
other.offset = calls.cend() - it;
}
return other;
}
/**
* @brief Returns a sink that connects before anything else.
* @return A properly initialized sink object.
*/
[[nodiscard]] sink before() {
sink other{*this};
other.offset = signal->calls.size();
return other;
}
/**
* @brief Connects a free function (with or without payload), a bound or an
* unbound member to a signal.
*
* The signal isn't responsible for the connected object or the payload, if
* any. Users must guarantee that the lifetime of the instance overcomes the
* one of the signal. On the other side, the signal handler performs
* checks to avoid multiple connections for the same function.<br/>
* When used to connect a free function with payload, its signature must be
* such that the instance is the first argument before the ones used to
* define the signal itself.
*
* @tparam Candidate Function or member to connect to the signal.
* @tparam Type Type of class or type of payload, if any.
* @param value_or_instance A valid object that fits the purpose, if any.
* @return A properly initialized connection object.
*/
template<auto Candidate, typename... Type>
connection connect(Type &&...value_or_instance) {
disconnect<Candidate>(value_or_instance...);
delegate<Ret(Args...)> call{};
call.template connect<Candidate>(value_or_instance...);
signal->calls.insert(signal->calls.end() - offset, std::move(call));
delegate<void(void *)> conn{};
conn.template connect<&release<Candidate, Type...>>(value_or_instance...);
return {std::move(conn), signal};
}
/**
* @brief Disconnects a free function (with or without payload), a bound or
* an unbound member from a signal.
* @tparam Candidate Function or member to disconnect from the signal.
* @tparam Type Type of class or type of payload, if any.
* @param value_or_instance A valid object that fits the purpose, if any.
*/
template<auto Candidate, typename... Type>
void disconnect(Type &&...value_or_instance) {
auto &calls = signal->calls;
delegate<Ret(Args...)> call{};
call.template connect<Candidate>(value_or_instance...);
calls.erase(std::remove(calls.begin(), calls.end(), std::move(call)), calls.end());
}
/**
* @brief Disconnects free functions with payload or bound members from a
* signal.
* @tparam Type Type of class or type of payload.
* @param value_or_instance A valid object that fits the purpose.
*/
template<typename Type, typename = std::enable_if_t<!std::is_same_v<std::decay_t<std::remove_pointer_t<Type>>, void>>>
void disconnect(Type &value_or_instance) {
disconnect(&value_or_instance);
}
/**
* @brief Disconnects free functions with payload or bound members from a
* signal.
* @param value_or_instance A valid object that fits the purpose.
*/
void disconnect(const void *value_or_instance) {
if(value_or_instance) {
auto &calls = signal->calls;
auto predicate = [value_or_instance](const auto &delegate) { return delegate.data() == value_or_instance; };
calls.erase(std::remove_if(calls.begin(), calls.end(), std::move(predicate)), calls.end());
}
}
/*! @brief Disconnects all the listeners from a signal. */
void disconnect() {
signal->calls.clear();
}
private:
difference_type offset;
signal_type *signal;
};
/**
* @brief Deduction guide.
*
* It allows to deduce the signal handler type of a sink directly from the
* signal it refers to.
*
* @tparam Ret Return type of a function type.
* @tparam Args Types of arguments of a function type.
* @tparam Allocator Type of allocator used to manage memory and elements.
*/
template<typename Ret, typename... Args, typename Allocator>
sink(sigh<Ret(Args...), Allocator> &) -> sink<sigh<Ret(Args...), Allocator>>;
} // namespace entt
#endif