src/common/optional.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005, 2006 Christian Schoenebeck                        *
 *                                                                         *
 *   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 2 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, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_OPTIONAL_H__
#define __LS_OPTIONAL_H__

#include "Exception.h"

namespace LinuxSampler {

    class optional_base {
        public:
            class nothing_t { public: nothing_t() {} };

            static const nothing_t nothing;
    };

    template<class T>
    class optional : public optional_base {
        public:
            optional() {
                initialized = false;
            }

            optional(T data) {
                this->data  = data;
                initialized = true;
            }

            optional(nothing_t) {
                initialized = false;
            }

            template <class T_inner>
            optional(T_inner data) {
                this->data  = T(data);
                initialized = true;
            }

            const T& get() const throw (Exception) {
                if (!initialized) throw Exception("optional variable not initialized");
                return data;
            }

            T& get() throw (Exception) {
                if (!initialized) throw Exception("optional variable not initialized");
                return data;
            }

            optional& operator =(const optional& arg) throw (Exception) {
                if (!arg.initialized) throw Exception("optional variable not initialized");
                this->data  = arg.data;
                initialized = true;
                return *this;
            }

            optional& operator =(const T& arg) {
                this->data  = arg;
                initialized = true;
                return *this;
            }

            const T& operator *() const throw (Exception) { return get(); }
            T&       operator *()       throw (Exception) { return get(); }

            const T* operator ->() const throw (Exception) {
                if (!initialized) throw Exception("optional variable not initialized");
                return &data;
            }

            T* operator ->() throw (Exception) {
                if (!initialized) throw Exception("optional variable not initialized");
                return &data;
            }

            operator bool()   const { return initialized; }
            bool operator !() const { return !initialized; }

        protected:
            T    data;
            bool initialized;
    };

} // namespace LinuxSampler

#endif // __LS_OPTIONAL_H__
1	schoenebeck	123	/***************************************************************************
2			* *
3			* LinuxSampler - modular, streaming capable sampler *
4			* *
5			* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	schoenebeck	880	* Copyright (C) 2005, 2006 Christian Schoenebeck *
7	schoenebeck	123	* *
8			* This program is free software; you can redistribute it and/or modify *
9			* it under the terms of the GNU General Public License as published by *
10			* the Free Software Foundation; either version 2 of the License, or *
11			* (at your option) any later version. *
12			* *
13			* This program is distributed in the hope that it will be useful, *
14			* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16			* GNU General Public License for more details. *
17			* *
18			* You should have received a copy of the GNU General Public License *
19			* along with this program; if not, write to the Free Software *
20			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21			* MA 02111-1307 USA *
22			***************************************************************************/
23
24			#ifndef __LS_OPTIONAL_H__
25			#define __LS_OPTIONAL_H__
26
27	schoenebeck	880	#include "Exception.h"
28	schoenebeck	123
29			namespace LinuxSampler {
30
31			class optional_base {
32			public:
33			class nothing_t { public: nothing_t() {} };
34
35			static const nothing_t nothing;
36			};
37
38			template<class T>
39			class optional : public optional_base {
40			public:
41			optional() {
42			initialized = false;
43			}
44
45			optional(T data) {
46			this->data = data;
47			initialized = true;
48			}
49
50			optional(nothing_t) {
51			initialized = false;
52			}
53
54			template <class T_inner>
55			optional(T_inner data) {
56			this->data = T(data);
57			initialized = true;
58			}
59
60	schoenebeck	880	const T& get() const throw (Exception) {
61			if (!initialized) throw Exception("optional variable not initialized");
62	schoenebeck	123	return data;
63			}
64
65	schoenebeck	880	T& get() throw (Exception) {
66			if (!initialized) throw Exception("optional variable not initialized");
67	schoenebeck	123	return data;
68			}
69
70	schoenebeck	880	optional& operator =(const optional& arg) throw (Exception) {
71			if (!arg.initialized) throw Exception("optional variable not initialized");
72	schoenebeck	123	this->data = arg.data;
73			initialized = true;
74	schoenebeck	810	return *this;
75	schoenebeck	123	}
76
77			optional& operator =(const T& arg) {
78			this->data = arg;
79			initialized = true;
80	schoenebeck	810	return *this;
81	schoenebeck	123	}
82
83	schoenebeck	880	const T& operator *() const throw (Exception) { return get(); }
84			T& operator *() throw (Exception) { return get(); }
85	schoenebeck	123
86	schoenebeck	880	const T* operator ->() const throw (Exception) {
87			if (!initialized) throw Exception("optional variable not initialized");
88	schoenebeck	123	return &data;
89			}
90
91	schoenebeck	880	T* operator ->() throw (Exception) {
92			if (!initialized) throw Exception("optional variable not initialized");
93	schoenebeck	123	return &data;
94			}
95
96			operator bool() const { return initialized; }
97	senkov	134	bool operator !() const { return !initialized; }
98	schoenebeck	123
99			protected:
100			T data;
101			bool initialized;
102			};
103
104			} // namespace LinuxSampler
105
106			#endif // __LS_OPTIONAL_H__