serenity/AK/ScopeGuard.h
Nico Weber e4c36876d2 AK: Make Function a little bit constexpr
Just enough to make it possible to pass a lambda to a constexpr function
taking an AK::Function parameter and have that constexpr function call
the passed-in AK::Function.

The main thing is that bit_cast<>s of pointers aren't ok in constexpr
functions, and neither is placement new. So add a union with stronger
typing for the constexpr case.

The body of the `if (is_constexpr_evaluated())` in
`init_with_callable()` is identical to the `if constexpr` right
after it. But `if constexpr (is_constexpr_evaluated())` always
evaluates `is_constexpr_evaluated()` in a constexpr context, so
this can't just add ` || is_constexpr_evaluated()` to that
`if constexpr`.
2024-12-20 12:05:06 -05:00

56 lines
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C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/StdLibExtras.h>
namespace AK {
template<typename Callback>
class ScopeGuard {
public:
constexpr ScopeGuard(Callback callback)
: m_callback(move(callback))
{
}
constexpr ~ScopeGuard()
{
m_callback();
}
private:
Callback m_callback;
};
template<typename Callback>
class ArmedScopeGuard {
public:
ArmedScopeGuard(Callback callback)
: m_callback(move(callback))
{
}
~ArmedScopeGuard()
{
if (m_armed)
m_callback();
}
void disarm() { m_armed = false; }
private:
Callback m_callback;
bool m_armed { true };
};
}
#if USING_AK_GLOBALLY
using AK::ArmedScopeGuard;
using AK::ScopeGuard;
#endif