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	schoenebeck	123	/***************************************************************************
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__