ladybird/AK/TypeCasts.h
Andreas Kling ee3a73ddbb AK: Rename downcast<T> => verify_cast<T>
This makes it much clearer what this cast actually does: it will
VERIFY that the thing we're casting is a T (using is<T>()).
2021-06-24 19:57:01 +02:00

50 lines
1.3 KiB
C++

/*
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Assertions.h>
#include <AK/Platform.h>
#include <AK/StdLibExtras.h>
namespace AK {
template<typename OutputType, typename InputType>
ALWAYS_INLINE bool is(InputType& input)
{
if constexpr (requires { input.template fast_is<OutputType>(); }) {
return input.template fast_is<OutputType>();
}
return dynamic_cast<CopyConst<InputType, OutputType>*>(&input);
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE bool is(InputType* input)
{
return input && is<OutputType>(*input);
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>* verify_cast(InputType* input)
{
static_assert(IsBaseOf<InputType, OutputType>);
VERIFY(!input || is<OutputType>(*input));
return static_cast<CopyConst<InputType, OutputType>*>(input);
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>& verify_cast(InputType& input)
{
static_assert(IsBaseOf<InputType, OutputType>);
VERIFY(is<OutputType>(input));
return static_cast<CopyConst<InputType, OutputType>&>(input);
}
}
using AK::is;
using AK::verify_cast;