stduuid/README.md

stduuid

A C++ cross-platform implementation for universally unique identifiers, simply know as either UUID or GUID (mostly on Windows). A UUID is a 128-bit number used to uniquely identify information in computer systems, such as database table keys, COM interfaces, classes and type libraries, and many others.

For information about UUID/GUIDs see:

• Universally unique identifier
• A Universally Unique IDentifier (UUID) URN Namespace

Library overview

The library defines a namespace uuids with the following types and functions:

• uuid is a class representing a UUID; this can be default constructed (a nil UUID), constructed from an array of bytes, or from a string. sentation (in lowercase)
• uuid_variant is a strongly type enum representing the type of a UUID
• uuid_version is a strongly type enum representing the version of a UUID
• make_uuid is a parameterless function that creates a new UUID using the typical platform-specific method to create one (CoCreateGuid on Windows, uuid_generate on Linux, CFUUIDCreate on Mac).
• operator== and operator!= for UUIDs comparison
• operator<< to write a UUID to an output string using the standard repre

This project is currently under development and should be ignored until further notice.

Using the library

The following is a list of examples for using the library:

• Creating a nil UUID

uuid empty;
assert(empty.is_nil());
assert(empty.size() == 16);

• Creating a new UUID

uuid const guid = uuids::make_uuid();
assert(!guid.is_nil());
assert(guid.size() == 16);
assert(guid.version() == uuids::uuid_version::random_number_based);
assert(guid.variant() == uuids::uuid_variant::rfc);

• Create a UUID from a string

using namespace std::string_literals;

auto str = "47183823-2574-4bfd-b411-99ed177d3e43"s;
uuid guid(str);
assert(guid.string() == str);

or

auto str = L"47183823-2574-4bfd-b411-99ed177d3e43"s;
uuid guid(str);
assert(guid.wstring() == str);      

• Comparing UUIDS

uuid empty;
uuid guid = uuids::make_uuid();

assert(empty == empty);
assert(guid == guid);
assert(empty != guid);

• Swapping UUIDS

uuid empty;
uuid guid = uuids::make_uuid();

assert(empty.is_nil());
assert(!guid.is_nil());

std::swap(empty, guid);

assert(!empty.is_nil());
assert(guid.is_nil());

empty.swap(guid);

assert(empty.is_nil());
assert(!guid.is_nil());

• Convert to string

uuid empty;
assert(empty.string() == "00000000-0000-0000-0000-000000000000");
assert(empty.wstring() == L"00000000-0000-0000-0000-000000000000");