tiny_rand

A small header-only library to randomly generate data.

Useful to quickly generate test samples without requiring a big library as dependency.

Features

A small API that allows to generate any kind of STL data structures:

• Primitives: int, double, strings, ...
• Containers: vector, list, maps, sets, ...
• Product types: tuples, and custom struct or classes.
• Sum types: variants, optionals, ...

It does so by allowing to combine generator together to produce any kind of data.

You can find here a blog post introducing the rationale and the design further.

Examples

Generating a custom data structure rgb_color in a few lines of code and printing the result:

struct rgb_color
{
   int m_red;
   int m_green;
   int m_blue;
};

rgb_color make_rgb_color(int red, int green, int blue)
{
   return rgb_color{ red, green, blue };
}

void rgb_color_samples(std::mt19937& bit_gen)
{
   using namespace tiny_rand;
   auto color_gen = int_gen(0, 255);
   auto rgb_color_gen = apply_gen(make_rgb_color, color_gen, color_gen, color_gen);

   std::cout << "Generating colors\n";
   for (auto c : vector_gen(10, rgb_color_gen)(bit_gen))
      std::cout << c << '\n';
}

Generating an instance of a game object, that contains an integer for the current round number, and a map from player names to their respective 3D position:

using PlayerName = std::string;
using Coordinate = std::tuple<double, double, double>;

struct Game
{
   int m_current_round;
   std::map<PlayerName, Coordinate> m_players_location;
};

auto round_gen()
{
   return int_gen(0, std::numeric_limits<int>::max());
}

auto player_name_gen()
{
   return string_gen(
      int_gen(1, 30), //Player name cannot be empty
      alphanum_gen()  //Restriction on the character set
   );
}

auto coord_3d_gen(double map_size)
{
   auto coord_1d_gen = double_gen(0, map_size);
   return tuple_gen(coord_1d_gen, coord_1d_gen, coord_1d_gen);
}

auto game_gen(int max_player, double map_size)
{
   return apply_gen(
      to_object<Game>(), //Combine into a game
      round_gen(),
      sorted_map_gen(max_player,
                     player_name_gen(),
                     coord_3d_gen(map_size))
   );
}