Files
ladybird/AK/TypeCasts.h
Andreas Kling b7ba863bf7 AK: Avoid double "is" check in as_if<T> when type must be dynamic_casted
Before this change, the is<T> check simplified down to a dynamic_cast,
which meant we did two dynamic_casts in a row for no reason.
2025-12-20 09:13:19 -06:00

93 lines
2.4 KiB
C++

/*
* Copyright (c) 2020-2021, Andreas Kling <andreas@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Assertions.h>
#include <AK/Concepts.h>
#include <AK/Forward.h>
#include <AK/Platform.h>
namespace AK {
template<typename OutputType, typename InputType>
ALWAYS_INLINE bool is(InputType& input)
{
static_assert(!SameAs<RemoveCVReference<OutputType>, RemoveCVReference<InputType>>);
if constexpr (requires { input.template fast_is<RemoveCVReference<OutputType>>(); }) {
return input.template fast_is<RemoveCVReference<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 bool is(NonnullRefPtr<InputType> const& input)
{
return is<OutputType>(*input);
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>* as_if(InputType& input)
{
if constexpr (requires { static_cast<CopyConst<InputType, OutputType>*>(&input); }) {
if (!is<OutputType>(input))
return nullptr;
return static_cast<CopyConst<InputType, OutputType>*>(&input);
}
return dynamic_cast<CopyConst<InputType, OutputType>*>(&input);
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>* as_if(InputType* input)
{
if (!input)
return nullptr;
return as_if<OutputType>(*input);
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>& as(InputType& input)
{
auto* result = as_if<OutputType>(input);
VERIFY(result);
return *result;
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>* as(InputType* input)
{
if (!input)
return nullptr;
auto* result = as_if<OutputType>(input);
VERIFY(result);
return result;
}
template<typename OutputType, typename InputType>
ALWAYS_INLINE CopyConst<InputType, OutputType>* bridge_cast(InputType input)
{
#ifdef AK_HAS_OBJC_ARC
return (__bridge CopyConst<InputType, OutputType>*)(input);
#else
return static_cast<CopyConst<InputType, OutputType>*>(input);
#endif
}
}
#if USING_AK_GLOBALLY
using AK::as;
using AK::as_if;
using AK::bridge_cast;
using AK::is;
#endif