CRNOption.h

Go to the documentation of this file.

/* Copyright 2011-2015 CoReNum, INSA-Lyon, Universite Paris Descartes
 * 
 * This file is part of libcrn.
 * 
 * libcrn is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * libcrn 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with libcrn.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * file: CRNOption.h
 * \author Yann LEYDIER
 */

#ifndef CRNOption_HEADER
#define CRNOption_HEADER

namespace crn
{
    template<typename T> class Option
    {
        public:
            constexpr Option() noexcept : var(nullptr) {}
            inline Option(const T &value):var(new T(value)) {}
            inline Option(const Option &o)
            {
                if (o.var) var = new T(*(o.var));
                else var = nullptr;
            }
            inline Option(Option &&o) noexcept : var(o.var) { o.var = nullptr; }
            inline Option& operator=(const Option &o)
            {
                if (&o == this) return *this;
                if (o.var)
                {
                    if (var) *var = *(o.var);
                    else var = new T(*(o.var));
                }
                else if (var) { delete var; var = nullptr; }
                return *this;
            }
            inline Option& operator=(Option &&o) noexcept { if (&o == this) return *this; delete var; var = o.var; o.var = nullptr; return *this; }
            inline ~Option() { delete var; }
            inline operator bool() const noexcept { return var != nullptr; }
            inline T& Get() noexcept { return *var; }
            inline const T& Get() const noexcept { return *var; }
            inline T& operator*() noexcept { return *var; }
            inline const T& operator*() const noexcept { return *var; }
            inline T* operator->() noexcept { return var; }
            inline const T* operator->() const noexcept { return var; }
        private:
            T *var; 
    };
}

#endif