std::discrete_distribution::discrete_distribution(3)

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.