You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
237 lines
5.5 KiB
237 lines
5.5 KiB
#pragma once
|
|
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
|
|
// BUG: none of this is in a namespace
|
|
// TODO: Specify the concept of an iterator
|
|
|
|
/**
|
|
* @brief An enumeration that may be used to determine iterator categories
|
|
*
|
|
*/
|
|
enum class iterator_type_t{
|
|
contiguous_iterator, /**< Defines an iterator for something that is continuous and random access */
|
|
non_contiguous_iterator, /**< Defines an iterator for a non contiguous datastructure, for example an iterator over a hashmap or a tree*/
|
|
lazy_iterator /**< Defines an iterator for which the actual data layout and availability are still unknown*/
|
|
};
|
|
|
|
/**
|
|
* @brief An abstraction of a pointer to iterate against, in both normal and reverse order
|
|
*
|
|
* @tparam T The type of data pointed by the iterator
|
|
* @tparam sign the direction in which data is scrutinized, should be either 1 or -1, behaviour for other value is left undefined
|
|
*/
|
|
template<typename T, int sign = 1>
|
|
struct pointer_iterator final
|
|
{
|
|
T* data; /**< the only data field of the class */
|
|
typedef T value_type; /**< The type of which a reference will be returned on dereferencing */
|
|
typedef std::size_t difference_type; /**< The type of the substraction of two pointers */
|
|
static constexpr iterator_type_t iterator_type = iterator_type_t::contiguous_iterator; /**< @see iterator_type_t */
|
|
|
|
/**
|
|
* @brief Generates an empty iterator
|
|
*/
|
|
constexpr pointer_iterator()
|
|
: data{nullptr}
|
|
{}
|
|
|
|
constexpr pointer_iterator(const pointer_iterator& oth)
|
|
: data{oth.data}
|
|
{}
|
|
|
|
/**
|
|
* @brief Generates an iterator from any pointer
|
|
*/
|
|
constexpr pointer_iterator(T* ptr)
|
|
: data{ptr}
|
|
{}
|
|
|
|
/**
|
|
* @brief Dereference unary operator
|
|
*
|
|
* @return constexpr T& returns a reference to the pointed value
|
|
*/
|
|
constexpr T& operator*() const
|
|
{
|
|
return *data;
|
|
}
|
|
|
|
constexpr pointer_iterator& operator++()
|
|
{
|
|
data += sign;
|
|
return *this;
|
|
}
|
|
|
|
constexpr pointer_iterator operator++(int)
|
|
{
|
|
auto p = *this;
|
|
data += sign;
|
|
return p;
|
|
}
|
|
|
|
constexpr pointer_iterator& operator--()
|
|
{
|
|
data -= sign;
|
|
return *this;
|
|
}
|
|
|
|
constexpr pointer_iterator operator--(int)
|
|
{
|
|
auto p = *this;
|
|
data -= sign;
|
|
return p;
|
|
}
|
|
|
|
constexpr pointer_iterator operator+(const std::size_t offset) const
|
|
{
|
|
return pointer_iterator{data+sign*offset};
|
|
}
|
|
|
|
constexpr pointer_iterator operator+(const int offset) const
|
|
{
|
|
return pointer_iterator{data+sign*offset};
|
|
}
|
|
|
|
constexpr pointer_iterator operator-(const std::size_t offset) const
|
|
{
|
|
return pointer_iterator{data-sign*offset};
|
|
}
|
|
|
|
constexpr pointer_iterator operator-(const int offset) const
|
|
{
|
|
return pointer_iterator{data-sign*offset};
|
|
}
|
|
|
|
constexpr difference_type operator-(const pointer_iterator& oth) const
|
|
{
|
|
return ((T*)data-(T*)oth.data)*sign;
|
|
}
|
|
|
|
constexpr bool operator==(const pointer_iterator oth) const
|
|
{
|
|
return data==oth.data;
|
|
}
|
|
|
|
constexpr bool operator!=(pointer_iterator oth) const
|
|
{
|
|
return data!=oth.data;
|
|
}
|
|
|
|
constexpr bool before_or_equal(const pointer_iterator oth) const
|
|
{
|
|
return reinterpret_cast<std::intptr_t>(data) <= reinterpret_cast<std::intptr_t>(oth.data);
|
|
}
|
|
|
|
constexpr bool operator<=(const pointer_iterator oth) const
|
|
{
|
|
return before_or_equal(oth);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* @brief An identical twin to the pointer_iterator, but which dereference to a const reference
|
|
*
|
|
* @see pointer_iterator
|
|
* @tparam T @see pointer_iterator
|
|
* @tparam sign @see pointer_iterator
|
|
*/
|
|
template<typename T, int sign = 1>
|
|
struct const_pointer_iterator final
|
|
{
|
|
const T* data; /**< @see pointer_iterator */
|
|
typedef T value_type; /**< @see pointer_iterator */
|
|
typedef std::size_t difference_type; /**< @see pointer_iterator */
|
|
static constexpr iterator_type_t iterator_type = iterator_type_t::contiguous_iterator; /**< @see pointer_iterator */
|
|
|
|
constexpr const_pointer_iterator(const const_pointer_iterator& oth)
|
|
: data{oth.data}
|
|
{}
|
|
|
|
/**
|
|
* @brief @see pointer_iterator
|
|
*/
|
|
constexpr const_pointer_iterator(const T* ptr)
|
|
: data{ptr}
|
|
{}
|
|
|
|
/**
|
|
* @brief Dereferencing returns a const version of what a pointer_iterator would return
|
|
*/
|
|
constexpr const T& operator*() const
|
|
{
|
|
return *data;
|
|
}
|
|
|
|
constexpr const_pointer_iterator& operator++()
|
|
{
|
|
data += sign;
|
|
return *this;
|
|
}
|
|
|
|
constexpr const_pointer_iterator operator++(int)
|
|
{
|
|
auto p = data;
|
|
data += sign;
|
|
return const_pointer_iterator{p};
|
|
}
|
|
|
|
constexpr const_pointer_iterator& operator--()
|
|
{
|
|
data -= sign;
|
|
return *this;
|
|
}
|
|
|
|
constexpr const_pointer_iterator operator--(int)
|
|
{
|
|
auto p = data;
|
|
data -= sign;
|
|
return const_pointer_iterator{p};
|
|
}
|
|
|
|
constexpr const_pointer_iterator operator+(const std::size_t offset) const
|
|
{
|
|
return const_pointer_iterator{data+sign*offset};
|
|
}
|
|
|
|
constexpr const_pointer_iterator operator+(const int offset) const
|
|
{
|
|
return const_pointer_iterator{data+sign*offset};
|
|
}
|
|
|
|
constexpr const_pointer_iterator operator-(const std::size_t offset) const
|
|
{
|
|
return const_pointer_iterator{data-sign*offset};
|
|
}
|
|
|
|
constexpr const_pointer_iterator operator-(const int offset)
|
|
{
|
|
return const_pointer_iterator{data-sign*offset};
|
|
}
|
|
|
|
constexpr difference_type operator-(const const_pointer_iterator& oth) const
|
|
{
|
|
return ((T*)data-(T*)oth.data)*sign;
|
|
}
|
|
|
|
constexpr bool operator==(const const_pointer_iterator oth) const
|
|
{
|
|
return data==oth.data;
|
|
}
|
|
|
|
constexpr bool operator!=(const_pointer_iterator oth) const
|
|
{
|
|
return data!=oth.data;
|
|
}
|
|
|
|
constexpr bool before_or_equal(const const_pointer_iterator oth) const
|
|
{
|
|
return reinterpret_cast<std::intptr_t>(data) <= reinterpret_cast<std::intptr_t>(oth.data);
|
|
}
|
|
|
|
constexpr bool operator<=(const const_pointer_iterator oth) const
|
|
{
|
|
return before_or_equal(oth);
|
|
}
|
|
};
|