src/common/optional.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 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 "LinuxSamplerException.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 (LinuxSamplerException) {
                if (!initialized) throw LinuxSamplerException("optional variable not initialized");
                return data;
            }

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

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

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

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

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

            T* operator ->() throw (LinuxSamplerException) {
                if (!initialized) throw LinuxSamplerException("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	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 Christian Schoenebeck *
7	* *
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	#include "LinuxSamplerException.h"
28
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	const T& get() const throw (LinuxSamplerException) {
61	if (!initialized) throw LinuxSamplerException("optional variable not initialized");
62	return data;
63	}
64
65	T& get() throw (LinuxSamplerException) {
66	if (!initialized) throw LinuxSamplerException("optional variable not initialized");
67	return data;
68	}
69
70	optional& operator =(const optional& arg) throw (LinuxSamplerException) {
71	if (!arg.initialized) throw LinuxSamplerException("optional variable not initialized");
72	this->data = arg.data;
73	initialized = true;
74	}
75
76	optional& operator =(const T& arg) {
77	this->data = arg;
78	initialized = true;
79	}
80
81	const T& operator *() const throw (LinuxSamplerException) { return get(); }
82	T& operator *() throw (LinuxSamplerException) { return get(); }
83
84	const T* operator ->() const throw (LinuxSamplerException) {
85	if (!initialized) throw LinuxSamplerException("optional variable not initialized");
86	return &data;
87	}
88
89	T* operator ->() throw (LinuxSamplerException) {
90	if (!initialized) throw LinuxSamplerException("optional variable not initialized");
91	return &data;
92	}
93
94	operator bool() const { return initialized; }
95	bool operator !() const { return !initialized; }
96
97	protected:
98	T data;
99	bool initialized;
100	};
101
102	} // namespace LinuxSampler
103
104	#endif // __LS_OPTIONAL_H__