Started documenting and added a doxygen config

also fixed some missing const when I saw them

.gitignore

@@ -42,3 +42,4 @@ README.html
 bin/tests.S
 bin/tests.S.zip
 vgcore.*
+doc/*

include/gp/iterator.hpp

@@ -1,22 +1,37 @@
 #pragma once
 
-#include <stddef.h>
-#include <stdint.h>
+#include <cstddef>
+#include <cstdint>
 
+// BUG: none of this is in a namespace
+
+/**
+ * @brief An enumeration that may be used to determine iterator categories
+ * 
+ */
 enum class iterator_type_t{
-	contiguous_iterator,
-	non_contiguous_iterator,
-	lazy_iterator
+	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;
-	typedef T value_type;
-	typedef std::size_t difference_type;
-	static constexpr iterator_type_t iterator_type = iterator_type_t::contiguous_iterator;
-
+	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}
 	{}
@@ -25,11 +40,19 @@ struct pointer_iterator final
 	: data{oth.data}
 	{}
 
+	/**
+	 * @brief Generates an iterator from any pointer
+	 */
 	constexpr pointer_iterator(T* ptr)
 	: data{ptr}
 	{}
 
-	constexpr T& operator*()
+	/**
+	 * @brief Dereference unary operator
+	 * 
+	 * @return constexpr T& returns a reference to the pointed value
+	 */
+	constexpr T& operator*() const
 	{
 		return *data;
 	}
@@ -60,22 +83,22 @@ struct pointer_iterator final
 		return p;
 	}
 
-	constexpr pointer_iterator operator+(const std::size_t offset)
+	constexpr pointer_iterator operator+(const std::size_t offset) const
 	{
 		return pointer_iterator{data+sign*offset};
 	}
 
-	constexpr pointer_iterator operator+(const int offset)
+	constexpr pointer_iterator operator+(const int offset) const
 	{
 		return pointer_iterator{data+sign*offset};
 	}
 
-	constexpr pointer_iterator operator-(const std::size_t offset)
+	constexpr pointer_iterator operator-(const std::size_t offset) const
 	{
 		return pointer_iterator{data-sign*offset};
 	}
 
-	constexpr pointer_iterator operator-(const int offset)
+	constexpr pointer_iterator operator-(const int offset) const
 	{
 		return pointer_iterator{data-sign*offset};
 	}
@@ -85,44 +108,57 @@ struct pointer_iterator final
 		return ((T*)data-(T*)oth.data)*sign;
 	}
 
-	constexpr bool operator==(const pointer_iterator oth)
+	constexpr bool operator==(const pointer_iterator oth) const
 	{
 		return data==oth.data;
 	}
 
-	constexpr bool operator!=(pointer_iterator oth)
+	constexpr bool operator!=(pointer_iterator oth) const
 	{
 		return data!=oth.data;
 	}
 
-	constexpr bool before_or_equal(const pointer_iterator oth)
+	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)
+	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;
-	typedef T value_type;
-	typedef std::size_t difference_type;
-	static constexpr iterator_type_t iterator_type = iterator_type_t::contiguous_iterator;
+	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}
 	{}
 
-	constexpr const T& operator*()
+	/**
+	 * @brief Dereferencing returns a const version of what a pointer_iterator would return
+	 */
+	constexpr const T& operator*() const
 	{
 		return *data;
 	}
@@ -153,17 +189,17 @@ struct const_pointer_iterator final
 		return const_pointer_iterator{p};
 	}
 
-	constexpr const_pointer_iterator operator+(const std::size_t 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)
+	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)
+	constexpr const_pointer_iterator operator-(const std::size_t offset) const
 	{
 		return const_pointer_iterator{data-sign*offset};
 	}
@@ -178,22 +214,22 @@ struct const_pointer_iterator final
 		return ((T*)data-(T*)oth.data)*sign;
 	}
 
-	constexpr bool operator==(const const_pointer_iterator oth)
+	constexpr bool operator==(const const_pointer_iterator oth) const
 	{
 		return data==oth.data;
 	}
 
-	constexpr bool operator!=(const_pointer_iterator oth)
+	constexpr bool operator!=(const_pointer_iterator oth) const
 	{
 		return data!=oth.data;
 	}
 
-	constexpr bool before_or_equal(const const_pointer_iterator oth)
+	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)
+	constexpr bool operator<=(const const_pointer_iterator oth) const
 	{
 		return before_or_equal(oth);
 	}