ladybird/AK/Span.h

198 lines
4.7 KiB
C++

/*
* Copyright (c) 2020, the SerenityOS developers.
* 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 {
namespace Detail {
template<typename T>
class Span {
public:
ALWAYS_INLINE Span() = default;
ALWAYS_INLINE Span(T* values, size_t size)
: m_values(values)
, m_size(size)
{
}
protected:
T* m_values { nullptr };
size_t m_size { 0 };
};
template<>
class Span<u8> {
public:
ALWAYS_INLINE Span() = default;
ALWAYS_INLINE Span(u8* values, size_t size)
: m_values(values)
, m_size(size)
{
}
ALWAYS_INLINE Span(void* values, size_t size)
: m_values(reinterpret_cast<u8*>(values))
, m_size(size)
{
}
protected:
u8* m_values { nullptr };
size_t m_size { 0 };
};
template<>
class Span<const u8> {
public:
ALWAYS_INLINE Span() = default;
ALWAYS_INLINE Span(const u8* values, size_t size)
: m_values(values)
, m_size(size)
{
}
ALWAYS_INLINE Span(const void* values, size_t size)
: m_values(reinterpret_cast<const u8*>(values))
, m_size(size)
{
}
ALWAYS_INLINE Span(const char* values, size_t size)
: m_values(reinterpret_cast<const u8*>(values))
, m_size(size)
{
}
protected:
const u8* m_values { nullptr };
size_t m_size { 0 };
};
}
template<typename T>
class Span : public Detail::Span<T> {
public:
using Iterator = T*;
using ConstIterator = const T*;
static_assert(!IsPointer<T>::value);
using Detail::Span<T>::Span;
ALWAYS_INLINE Span(std::nullptr_t)
: Span()
{
}
ALWAYS_INLINE Span(const Span& other)
: Span(other.m_values, other.m_size)
{
}
ALWAYS_INLINE const T* data() const { return this->m_values; }
ALWAYS_INLINE T* data() { return this->m_values; }
ALWAYS_INLINE ConstIterator begin() const
{
return this->m_values;
}
ALWAYS_INLINE ConstIterator end() const
{
return begin() + size();
}
ALWAYS_INLINE Iterator begin()
{
return this->m_values;
}
ALWAYS_INLINE Iterator end()
{
return begin() + size();
}
ALWAYS_INLINE size_t size() const { return this->m_size; }
ALWAYS_INLINE bool is_empty() const { return this->m_size == 0; }
ALWAYS_INLINE Span slice(size_t start, size_t size) const
{
ASSERT(start + size <= this->m_size);
return { this->m_values + start, size };
}
ALWAYS_INLINE T* offset(size_t start) const
{
ASSERT(start < this->m_size);
return this->m_values + start;
}
ALWAYS_INLINE const T& at(size_t index) const
{
ASSERT(index < this->m_size);
return this->m_values[index];
}
ALWAYS_INLINE T& at(size_t index)
{
ASSERT(index < this->m_size);
return this->m_values[index];
}
ALWAYS_INLINE T& operator[](size_t index) const
{
return this->m_values[index];
}
ALWAYS_INLINE T& operator[](size_t index)
{
return this->m_values[index];
}
ALWAYS_INLINE T& operator=(const T& other)
{
this->m_size = other.m_size;
this->m_values = other.m_values;
}
ALWAYS_INLINE operator Span<const T>() const
{
return { data(), size() };
}
};
using ReadonlyBytes = Span<const u8>;
using Bytes = Span<u8>;
}
using AK::Bytes;
using AK::ReadonlyBytes;
using AK::Span;