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/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in input and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of input code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <AK/StdLibExtras.h>
namespace AK {
template<typename OutputType, typename InputType, bool is_base_type = IsBaseOf<OutputType, InputType>::value>
struct TypeTraits {
static bool has_type(InputType&)
{
static_assert(IsVoid<OutputType>::value, "No TypeTraits for this type");
return false;
}
};
template<typename OutputType, typename InputType>
struct TypeTraits<OutputType, InputType, true> {
static bool has_type(InputType&) { return true; }
};
template<typename OutputType, typename InputType>
inline bool is(InputType* input)
{
return input && TypeTraits<const OutputType, const InputType>::has_type(*input);
}
template<typename OutputType, typename InputType>
inline bool is(InputType& input)
{
return TypeTraits<const OutputType, const InputType>::has_type(input);
}
template<typename OutputType, typename InputType>
inline CopyConst<InputType, OutputType>* downcast(InputType* input)
{
static_assert(IsBaseOf<InputType, OutputType>::value);
ASSERT(!input || is<OutputType>(*input));
return static_cast<CopyConst<InputType, OutputType>*>(input);
}
template<typename OutputType, typename InputType>
inline CopyConst<InputType, OutputType>& downcast(InputType& input)
{
static_assert(IsBaseOf<InputType, OutputType>::value);
ASSERT(is<OutputType>(input));
return static_cast<CopyConst<InputType, OutputType>&>(input);
}
#define AK_BEGIN_TYPE_TRAITS(ClassName) \
namespace AK { \
template<typename InputType> \
class TypeTraits<const ClassName, InputType, false> { \
public: \
static bool has_type(InputType& input) { return is_type(input); } \
\
private:
#define AK_END_TYPE_TRAITS() \
} \
; \
}
}
using AK::downcast;
using AK::is;
using AK::TypeTraits;
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