renderd7/include/renderd7/parameter.hpp

153 lines
3.8 KiB
C++

/**
* This file is part of RenderD7
* Copyright (C) 2021-2024 NPI-D7, tobid7
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <tuple>
namespace RenderD7 {
class Parameter {
private:
using id = size_t;
template <typename T>
struct type {
static void id() {}
};
template <typename T>
static id type_id() {
return reinterpret_cast<id>(&type<T>::id);
}
template <typename T>
using decay = typename std::decay<T>::type;
template <typename T>
using none =
typename std::enable_if<!std::is_same<Parameter, T>::value>::type;
struct base {
virtual ~base() {}
virtual bool is(id) const = 0;
virtual base *copy() const = 0;
} *p = nullptr;
template <typename T>
struct data : base, std::tuple<T> {
using std::tuple<T>::tuple;
T &get() & { return std::get<0>(*this); }
T const &get() const & { return std::get<0>(*this); }
bool is(id i) const override { return i == type_id<T>(); }
base *copy() const override { return new data{get()}; }
};
template <typename T>
T &stat() {
return static_cast<data<T> &>(*p).get();
}
template <typename T>
T const &stat() const {
return static_cast<data<T> const &>(*p).get();
}
template <typename T>
T &dyn() {
return dynamic_cast<data<T> &>(*p).get();
}
template <typename T>
T const &dyn() const {
return dynamic_cast<data<T> const &>(*p).get();
}
public:
/**
* @brief Default constructor
*/
Parameter() {}
/**
* @brief Destructs the Parameter
*/
~Parameter() { delete p; }
/**
* @brief Copy constructor
* @param s The Parameter to copy
*/
Parameter(Parameter &&s) : p{s.p} { s.p = nullptr; }
/**
* @brief Const copy constructor
* @param s The Parameter to copy
*/
Parameter(Parameter const &s) : p{s.p->copy()} {}
/**
* @brief Initializes the Parameter with the given value
* @param x The value to initialize the Parameter with
*/
template <typename T, typename U = decay<T>, typename = none<U>>
Parameter(T &&x) : p{new data<U>{std::forward<T>(x)}} {}
/**
* @brief Overloads the assignment operator
* @param s The value to set the Parameter to
*/
Parameter &operator=(Parameter s) {
swap(*this, s);
return *this;
}
friend void swap(Parameter &s, Parameter &r) { std::swap(s.p, r.p); }
/**
* @brief Clears the Parameter
*/
void clear() {
delete p;
p = nullptr;
}
/**
* @brief Checks whether the Parameter is the given type
* @tparam T The type to check
* @return Whether the Parameter has the given type or not
*/
template <typename T>
bool is() const {
return p ? p->is(type_id<T>()) : false;
}
/**
* @brief Returns the value of the Parameter
* @tparam T The type of the Parameter
* @return The value of the Parameter
* @warning If the type of the Parameter doesn't match the type of it's stored
* value, it will result in undefined behaviour.
*/
template <typename T>
T &get() & {
return stat<T>();
}
};
} // namespace RenderD7