NAME¶

std::discrete_distribution::discrete_distribution - std::discrete_distribution::discrete_distribution

Synopsis¶

discrete_distribution(); (1) (since C++11)
template< class InputIt > (2) (since C++11)
discrete_distribution( InputIt first, InputIt last );
discrete_distribution( std::initializer_list<double> weights ); (3) (since C++11)
template< class UnaryOperation >

discrete_distribution( std::size_t count, double xmin, double (4) (since C++11)
xmax,

UnaryOperation unary_op );
explicit discrete_distribution( const param_type& params ); (5) (since C++11)

Constructs a new distribution object.

1) Default constructor. Constructs the distribution with a single weight p={1}. This
distribution will always generate 0.

2) Constructs the distribution with weights in the range [first, last). If first ==
last, the effects are the same as of the default constructor.

3) Constructs the distribution with weights in weights. Effectively calls
discrete_distribution(weights.begin(), weights.end()).

4) Constructs the distribution with count weights that are generated using function
unary_op. Each of the weights is equal to w
i = unary_op(xmin + δ(i + 0.5)), where δ =

(xmax − xmin)
count

and i ∈ {0, ..., count−1}. xmin and xmax must be such that δ > 0. If count == 0
the effects are the same as of the default constructor.

5) Constructs the distribution with params as the distribution parameters.

Parameters¶

the range of elements defining the numbers to use as weights. The type
first, last - of the elements referred by InputIterator must be convertible to
double
weights - initializer list containing the weights
unary operation function object that will be applied.

The signature of the function should be equivalent to the following:

Ret fun(const Type &a);
unary_op -
The signature does not need to have const &.
The type Type must be such that an object of type double can be
dereferenced and then implicitly converted to Type. The type Ret must
be such that an object of type double can be dereferenced and assigned
a value of type Ret.
params - the distribution parameter set

Type requirements¶

-
InputIt must meet the requirements of LegacyInputIterator.