src/common/optional.h

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