xso::generator — Class Types and Methods

Class Types

The xso::generator<State, Scrambler> class defines the following types:

Type	Definition
state_type	This is the State template parameter.
scrambler_type	This is the Scrambler template parameter.
word_type	This is the State::word_type.
result_type	This is the State::word_type.

Notes:

1. The word_type is either a 32-bit or 64-bit unsigned integer.
2. The result_type should be defined by the Scrambler, but for our generators and many others, the result_type is always identical to the word_type.

Class Methods

The xso::generator<State, Scrambler> class defines the following class methods:

Class Method	Return Type	Description
word_count()	std::size_t	Returns the number of words of state.
bit_count()	std::size_t	Returns the number of bits of state.
min()	result_type	Returns the smallest possible output word.
max()	result_type	Returns the largest possible output word.
xso_name()	std::string	Returns a string that can be used as a name for this generator.

Notes:

1. These are all declared as static constexpr.
2. The trivial min() and max() methods are needed to satisfy the std::uniform_random_bit_generator concept.
3. The xso_name() method combines the results of the State::xso_name() and the Scrambler::xso_name() class methods to produce an overall “name” for this generator that incorporates the various template parameters it depends on.

Example

Example: Print some generator parameters

#include <xoshiro.h>
int main()
{
    using rng = xso::rng;
    std::cout << "Generator Name:        " << rng::xso_name() << '\n';
    std::cout << "State:                 " << rng::state_engine_type::xso_name() << '\n';
    std::cout << "Scrambler:             " << rng::output_function_type::xso_name() << '\n';
    std::cout << "Number of state words: " << rng::word_count() << '\n';
    std::cout << "Number of state bits:  " << rng::bit_count() << '\n';
}

Output:

Generator Name:         xoshiro<4x64,17,45>star_star<5,7,1>
State:                  xoshiro<4x64,17,45>
Scrambler:              star_star<5,7,1>
Number of state words:  4
Number of state bits:   256

See Also

State
Scrambler