banan-os/BAN/include/BAN/Span.h

132 lines
2.3 KiB
C++

#pragma once
#include <BAN/Assert.h>
#include <BAN/Iterators.h>
#include <stddef.h>
namespace BAN
{
template<typename T>
class Span
{
public:
using value_type = T;
using size_type = size_t;
using iterator = IteratorSimple<T, Span>;
using const_iterator = ConstIteratorSimple<T, Span>;
public:
Span() = default;
Span(T*, size_type);
Span(Span<T>&);
template<typename S>
requires(is_same_v<T, const S>)
Span(const Span<S>&);
iterator begin() { return iterator(m_data); }
iterator end() { return iterator(m_data + m_size); }
const_iterator begin() const { return const_iterator(m_data); }
const_iterator end() const { return const_iterator(m_data + m_size); }
T& operator[](size_type);
const T& operator[](size_type) const;
T* data();
const T* data() const;
bool empty() const;
size_type size() const;
void clear();
Span slice(size_type, size_type = ~size_type(0));
private:
T* m_data = nullptr;
size_type m_size = 0;
};
template<typename T>
Span<T>::Span(T* data, size_type size)
: m_data(data)
, m_size(size)
{
}
template<typename T>
Span<T>::Span(Span& other)
: m_data(other.data())
, m_size(other.size())
{
}
template<typename T>
template<typename S>
requires(is_same_v<T, const S>)
Span<T>::Span(const Span<S>& other)
: m_data(other.data())
, m_size(other.size())
{
}
template<typename T>
T& Span<T>::operator[](size_type index)
{
ASSERT(m_data);
ASSERT(index < m_size);
return m_data[index];
}
template<typename T>
const T& Span<T>::operator[](size_type index) const
{
ASSERT(m_data);
ASSERT(index < m_size);
return m_data[index];
}
template<typename T>
T* Span<T>::data()
{
return m_data;
}
template<typename T>
const T* Span<T>::data() const
{
return m_data;
}
template<typename T>
bool Span<T>::empty() const
{
return m_size == 0;
}
template<typename T>
typename Span<T>::size_type Span<T>::size() const
{
return m_size;
}
template<typename T>
void Span<T>::clear()
{
m_data = nullptr;
m_size = 0;
}
template<typename T>
Span<T> Span<T>::slice(size_type start, size_type length)
{
ASSERT(m_data);
ASSERT(start <= m_size);
if (length == ~size_type(0))
length = m_size - start;
ASSERT(start + length <= m_size);
return Span(m_data + start, m_size - start - length);
}
}