#ifndef STRING32_HH

#define STRING32_HH

#include "narrow.hh"

#include <cassert>

#include <cstdint>

#include <type_traits>

// Given a buffer of max size 4GB, 32 bits are enough to address each position

// in that buffer.

// - On 32-bit systems we can use a pointer to a location in the buffer.

// - On 64-bit systems a pointer is too large (64 bit), but an index in the

//   buffer works fine. (An index works fine on 32-bit systems as well, but is

//   slightly less efficient).

// The String32 helper abstracts the difference between the two above

// approaches. In both cases it is a 32-bit type (hence the name). And on

// both 32/64-bit systems it uses the more efficient implementation.

using String32 = std::conditional_t<

	(sizeof(char*) > sizeof(uint32_t)), // is a pointer bigger than an uint32_t

	uint32_t,                           // yes -> use uint32_t

	const char*>;                       // no  -> directly use pointer

// convert string in buffer to String32

constexpr void toString32(const char* buffer, const char* str, uint32_t& result) {

	assert(buffer <= str);

	result = narrow<uint32_t>(str - buffer);

}

constexpr void toString32(const char* /*buffer*/, const char* str, const char*& result) {

	result = str;

}

// convert String32 back to string in buffer

[[nodiscard]] constexpr const char* fromString32(const char* buffer, uint32_t str32) {

	return buffer + str32;

}

[[nodiscard]] constexpr const char* fromString32(const char* /*buffer*/, const char* str32) {

	return str32;

}

#endif