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/****************************************************************************
* Copyright (C) from 2009 to Present EPAM Systems.
*
* This file is part of Indigo toolkit.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
***************************************************************************/
#ifndef __nullable__
#define __nullable__
#include "base_cpp/array.h"
#include "base_cpp/exception.h"
namespace indigo
{
DECL_EXCEPTION(NullableError);
template <typename T> class Nullable
{
public:
Nullable() : _has_value(false)
{
variable_name.readString("<Undefined>", true);
}
const T& get() const
{
if (!_has_value)
throw Error("\"%s\" variable was not set", variable_name.ptr());
return _value;
}
operator const T&() const
{
return get();
}
Nullable<T>& operator=(const T& value)
{
set(value);
return *this;
}
void set(const T& value)
{
_value = value;
_has_value = true;
}
void reset()
{
_has_value = false;
}
bool hasValue() const
{
return _has_value;
}
void setName(const char* name)
{
variable_name.readString(name, true);
}
DECL_TPL_ERROR(NullableError);
private:
T _value;
bool _has_value;
Array<char> variable_name;
};
} // namespace indigo
#endif // __nullable__
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