UUIDs in 10 Languages — Part 5: C++, Scala, and Dart

Welcome to the final installment of our UUID tour! In this part, we’ll dive into UUID implementations for C++, Scala, and Dart.

Each of these languages offers unique tools and paradigms — from C++ performance, to Scala's functional JVM ecosystem, to Dart's UI-centric tooling for Flutter.

⚙️ C++: UUIDs in a Systems Language

C++ does not include UUID generation in the standard library, but several robust libraries support it — most notably, Boost.

🔧 Using Boost UUID

Install Boost with UUID module (usually part of base Boost packages):

cpp

#include <boost/uuid/uuid.hpp>
#include <boost/uuid/uuid_generators.hpp>
#include <boost/uuid/uuid_io.hpp>
#include <iostream>

int main() {
    boost::uuids::uuid id = boost::uuids::random_generator()();
    std::cout << "UUID: " << id << std::endl;
}

📦 Boost Options

random_generator() → UUIDv4 (random)
name_generator(ns) → UUIDv5
string_generator() → Parse from string

✅ Best Practices

Use UUIDv4 for general uniqueness
Store as 16-byte array (uint8_t[16]) when compactness matters
Avoid reinventing the wheel — Boost handles spec compliance

☕ Scala: Functional Power on the JVM

Scala runs on the JVM, and UUIDs are fully supported via java.util.UUID.

🔧 Generate UUIDv4

scala

import java.util.UUID

val id = UUID.randomUUID()
println(s"UUID: $id")

🧪 Parse and Validate

scala

val maybeUuid = try {
  Some(UUID.fromString("550e8400-e29b-41d4-a716-446655440000"))
} catch {
  case _: IllegalArgumentException => None
}

🔁 Use in Play Framework

In Play JSON:

scala

import play.api.libs.json._

implicit val uuidFormat: Format[UUID] = Format(
  Reads.uuid,
  Writes { uuid => JsString(uuid.toString) }
)

✅ Best Practices

Use UUIDs in models and case classes
Validate UUID input with Try(UUID.fromString(...))
Use UUID as primary keys in Slick or Quill with MappedColumnType

🦄 Dart: UUIDs for Flutter and Beyond

Dart supports UUIDs through third-party packages, especially useful in Flutter apps.

🔧 Install UUID Package

bash

dart pub add uuid

📦 Generate UUID

dart

import 'package:uuid/uuid.dart';

void main() {
  var uuid = Uuid();
  var id = uuid.v4();
  print('UUIDv4: $id');
}

Supports:

uuid.v1() – Time-based UUID
uuid.v4() – Random UUID
uuid.v5(namespace, name) – Deterministic UUID

✅ Best Practices

Use UUIDv4 for randomness in client-generated IDs
Validate UUIDs before use with regex or uuid.validate()
Don't use UUIDs as secrets — treat them as opaque identifiers

📘 Summary Table

Language	Generation	Library/Module	Notes
C++	`random_generator()`	Boost UUID	Requires linking Boost libs
Scala	`UUID.randomUUID()`	Built-in via Java	Works with Play, Slick, Quill
Dart	`Uuid().v4()`	`uuid` package	Ideal for Flutter/Dart apps

Final Thoughts

That wraps up our five-part tour of UUIDs in 10 languages!

From system programming to functional paradigms to cross-platform UI dev, UUIDs show up everywhere — and each ecosystem brings its own tools and conventions.

If you’ve followed along from Python to Dart, you now have a cross-stack understanding of UUID generation, validation, and safe usage.

👋 Thanks for joining the series — and may your UUIDs always be unique (and properly formatted).

"UUIDs in 10 Languages" Part 5: C++, Scala, and Dart