std::extreme_value_distribution<RealType>:: a, b

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

Returns the parameters the distribution was constructed with.

1) Returns the a distribution parameter (location). The default value is 1.0 .
2) Returns the b distribution parameter (scale). The default value is 0.0 .

Parameters

(none)

Return value

1) The a distribution parameter (location).
2) The b distribution parameter (scale).

See also

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