// This file is a part of Framsticks SDK.  http://www.framsticks.com/
// Copyright (C) 2019-2024  Maciej Komosinski and Szymon Ulatowski.
// See LICENSE.txt for details.

#ifndef _NONSTD_SPAN_H_
#define _NONSTD_SPAN_H_

#include <string>
#include <vector>

// Remove this and use std::span when available (c++20)

template<class ElementType> class span
{
public:
	constexpr span() noexcept
	{
		data_ = NULL;
		size_ = 0;
	}
	constexpr span(ElementType* first, size_t count) noexcept
	{
		data_ = first;
		size_ = count;
	}
	constexpr span(ElementType* first, ElementType* end) noexcept
	{
		data_ = first;
		size_ = end - first;
	}
	template<size_t N> constexpr span(ElementType(&arr)[N]) noexcept
	{
		data_ = arr;
		size_ = N;
	}

	size_t size() const { return size_; }
	size_t size_bytes() const { return size_ * sizeof(ElementType); }
	ElementType& operator[](size_t idx) const { return data_[idx]; }

	ElementType* begin() const { return data_; }
	ElementType* end() const { return data_ + size_; }

protected:
	ElementType* data_;
	size_t size_;
};

inline std::string stringFromSpan(const span<uint8_t>& s) { return std::string(s.begin(), s.end()); }
inline std::string stringFromSpan(const span<char>& s) { return std::string(s.begin(), s.end()); }
// in both lines below, in the last argument, &*v.end() was replaced by front+size, because the debugging+extensive checking version of the STL library with std::vector complained when calling &*v.end().
inline span<uint8_t> spanFromVector(std::vector<uint8_t>& v) { return span<uint8_t>(&v.front(), ((uint8_t*)&v.front())+v.size()); }
inline span<uint8_t> spanFromVector(std::vector<char>& v) { return span<uint8_t>((uint8_t*)&v.front(), ((uint8_t*)&v.front())+v.size()); }

#endif