ladybird/AK/Utf32View.h
Kevin Meyer e0f4fdc9b4 AK: Assert non-empty Utf32View, when initialized with non-zero length
This was useful in debugging a nullptr dereference, which was happening
through later, but was caused by this inconsistent initialization.
2020-06-15 22:32:18 +02:00

67 lines
2.3 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source 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/Assertions.h>
#include <AK/Checked.h>
#include <AK/Types.h>
namespace AK {
class Utf32View {
public:
Utf32View() { }
Utf32View(const u32* codepoints, size_t length)
: m_codepoints(codepoints)
, m_length(length)
{
ASSERT(codepoints || length == 0);
}
const u32* codepoints() const { return m_codepoints; }
bool is_empty() const { return m_length == 0; }
size_t length() const { return m_length; }
Utf32View substring_view(size_t offset, size_t length) const
{
if (length == 0)
return {};
ASSERT(offset < m_length);
ASSERT(!Checked<size_t>::addition_would_overflow(offset, length));
ASSERT((offset + length) <= m_length);
return Utf32View(m_codepoints + offset, length);
}
private:
const u32* m_codepoints { nullptr };
size_t m_length { 0 };
};
}
using AK::Utf32View;