A tiny, URL-friendly, unique string ID generator for C++, implementation of ai's nanoid!

Can be Safe. It uses mt19937, a strong random generator with a seed from random_device by default, which is not cryptographically secure. However, the library can be expanded using an algorithm of choice (from OpenSSL, Crypto++, Botan, LibCrypto) using the API.

Compact. It uses more symbols than UUID (A-Za-z0-9_-) and has the same number of unique options in just 22 symbols instead of 36.

Fast. Nanoid is as fast as UUID but can be used in URLs.

Install with cmake:

1. Copy git repo to your destination
2. Use add_subdirectory and target_link_libraries to add to your project.
3. Or use cmake and make to build the project and use it as a library.

The default method uses URL-friendly symbols (A-Za-z0-9_-) and returns an ID with 21 characters (to have a collision probability similar to UUID v4).

std::string id = nanoid::generate();
//id := "Uakgb_J5m9g-0JDMbcJqLJ"

Symbols -,.() are not encoded in the URL. If used at the end of a link they could be identified as a punctuation symbol.

If you want to reduce ID length (and increase collisions probability), you can pass the size as an argument:

std::string id = nanoid::generate(10);
//id := "IRFa-VaY2b"

The async method can be used to simplify writing of asynchronous code.

auto id_fut = nanoid::generate_async();
//unrelated code here
std::string id = id_fut.get();
//id := "Uakgb_J5m9g-0JDMbcJqLJ"

If you want to change the ID's alphabet or length you can pass alphabet and size.

std::string id = nanoid::generate("1234567890abcdef", 10);
//id := "4f90d13a42"

Alphabet must contain 256 symbols or less. Otherwise, the generator will not be secure.

You can replace the default safe random generator using the nanoid::crypto_random_base or nanoid::crypto_random<G> class. For instance, to use a seed-based generator.

auto random = nanoid::crypto_random<std::ranlux24>(10);
auto id = nanoid::generate(random, "abcdef", 10);
//id := "fbaefaadeb"

• ai - nanoid
• codeyu - nanoid-net

The MIT License (MIT). Please see License File for more information.