Email Generator for C++

Requires C++23 (e.g., -std=c++23 for GCC/Clang, /std:c++latest for MSVC).

API Reference · Usage Guide · Data and Method · Releases

Email addresses in each country's style, for tests, fixtures and generated users. The local part follows the country's naming habits from a given name, family name, nickname and birth year, and the domain is a provider people use there. A safe option uses the reserved example.* domains.

Features

• Locale-matched Local Parts. ana.souza, a.souza85, souza_ana, handles: nine style profiles weight the shapes by country. Names are folded to ASCII (Ørsted is orsted) and particles skipped (da Silva is silva).

• Provider Domains by Country. Global webmail plus the providers of the country (web.de, uol.com.br, qq.com, ...), by weight.

• Safe for Tests. safe gives example.com, example.net or example.org (RFC 2606), so a message sent to the address reaches nobody.

• Deterministic Seeding. Per-call get_email(request, seed) for reproducible results, and seed() on the result for replaying a previous generation with the same request and data.

• Batch Generation. Generate thousands of results from one seed, on several threads with the same output for any thread count, optionally unique by a key, and stream them as JSON Lines or CSV (see the usage guide).

• Identical Everywhere. A seed gives the same result on every compiler, standard library and CPU (GCC, Clang, MSVC, Emscripten; x86-64 and ARM64), checked by known-answer tests.

• Extensible Data. Load your own TSV layers on top of the shipped data to add, change or remove entries (extend()), checked before they are applied.

• JSON and Replay. to_json() on every result, and a signature() recording the seed and the data it came from.

• Compiled-in Data. Define DASMIG_EMAIL_EMBED to build the lite tier into the program, for WebAssembly and other builds without files.

• Multi-Instance Support. Construct independent emg instances with their own data and random engine.

Integration

emailgen.hpp is the library released here. Keep core.hpp and the core/ directory (dasmig-core) in the same directory. Add

#include <dasmig/emailgen.hpp>

to the files you want to use it in, and supply the resources folder (or define DASMIG_EMAIL_EMBED).

Usage

#include <dasmig/emailgen.hpp>
#include <iostream>

auto& gen = dasmig::emg::instance(); // loads the lite tier

// The names are plain values; the country sets the style and the domain.
auto e = gen.get_email({.country = "DE", .given = "Zoë", .family = "Müller", .birth_year = 1988});
std::cout << e << '\n';        // [email protected]
std::cout << e.kind << '\n';   // free

// No names: a handle in the country's style.
std::cout << gen.get_email({.country = "JP"}) << '\n';

// An address that reaches nobody, for tests.
std::cout << gen.get_email({.given = "Sam", .family = "Lee", .safe = true}) << '\n'; // [email protected]

// The same seed gives the same result everywhere.
auto again = gen.get_email({.country = "DE", .given = "Zoë", .family = "Müller", .birth_year = 1988}, e.seed());

See the usage guide for everything else.

Building

make            # example
make test       # tests
make bench      # benchmarks, results in build/bench.tsv
make test-embed # tests with the lite tier compiled in
make coverage   # code coverage
make lint       # clang-tidy
make docs       # API docs
make embed      # regenerate dasmig/emailgen_data.hpp from resources/lite

Compiler Support

Tested with:

• Clang 18+ (-std=c++23)
• GCC 14+ (-std=c++23)
• MSVC 19.38+ (/std:c++latest)
• Emscripten 3.1.74

Dependencies

Dependency	Version	Bundled	Purpose
dasmig-core	1.4	Yes (core.hpp, core/)	Platform-independent random engine and distributions, data layers, JSON
Catch2	3.x	Yes (amalgamated)	Unit testing

Related Libraries

Library	Description
address-generator	Postal addresses with real streets by place
biodata-generator	Procedural human physical characteristics
birth-generator	Demographically plausible birthdays
city-generator	Weighted city selection by population
country-generator	Weighted country selection by population
device-generator	Devices, browsers, user agents and IP addresses that fit together
entity-generator	ECS-based entity generation
interest-generator	Religion, hobbies and favourite media by country, age and sex
name-generator	Culturally appropriate full names
nickname-generator	Gamer-style nicknames
occupation-generator	Employment status, education and occupation by country, age and sex
persona-generator

License

This library is released under the MIT License.

MIT License

Copyright (c) 2026 Diego Dasso Migotto