std::uniform_int_distribution<IntType>:: a, b

From cppreference.com
result_type a ( ) const ;
(1) (since C++11)
result_type b ( ) const ;
(2) (since C++11)

Returns the parameters the distribution has been constructed with.

1) Returns the a distribution parameter. It defines the minimum possibly generated value. The default value is 0 .
2) Returns the b distribution parameter. It defines the maximum possibly generated value. The default value is std:: numeric_limits < IntType > :: max ( ) .

Parameters

(none)

Return value

1) The a distribution parameter.
2) The b distribution parameter.

See also

(C++11)
gets or sets the distribution parameter object
(public member function)