Atmosphere/libraries/libstratosphere/include/stratosphere/sf/sf_out.hpp

/*
 * Copyright (c) 2018-2020 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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 "sf_common.hpp"
#include "cmif/sf_cmif_pointer_and_size.hpp"

namespace ams::sf {

    namespace impl {

        struct OutBaseTag{};

    }

    template<typename>
    struct IsOutForceEnabled : public std::false_type{};

    template<>
    struct IsOutForceEnabled<::ams::Result> : public std::true_type{};

    template<typename T>
    concept OutEnabled = (std::is_trivial<T>::value || IsOutForceEnabled<T>::value) && !std::is_pointer<T>::value;

    template<typename T> requires OutEnabled<T>
    class Out : public impl::OutBaseTag {
        public:
            static constexpr size_t TypeSize = sizeof(T);
        private:
            T *ptr;
        public:
            constexpr Out(uintptr_t p) : ptr(reinterpret_cast<T *>(p)) { /* ... */ }
            constexpr Out(T *p) : ptr(p) { /* ... */ }
            constexpr Out(const cmif::PointerAndSize &pas) : ptr(reinterpret_cast<T *>(pas.GetAddress())) { /* TODO: Is AMS_ABORT_UNLESS(pas.GetSize() >= sizeof(T)); necessary? */ }

            void SetValue(const T& value) const {
                *this->ptr = value;
            }

            const T &GetValue() const {
                return *this->ptr;
            }

            T *GetPointer() const {
                return this->ptr;
            }

            /* Convenience operators. */
            T &operator*() const {
                return *this->ptr;
            }

            T *operator->() const {
                return this->ptr;
            }
    };

    template<typename T>
    class Out<T *> {
        static_assert(!std::is_same<T, T>::value, "Invalid sf::Out<T> (Raw Pointer)");
    };

}