std::exponential_distribution<RealType>::exponential_distribution

From cppreference.com
exponential_distribution( ) : exponential_distribution( 1.0 ) { }
(1) (since C++11)
explicit exponential_distribution( RealType lambda );
(2) (since C++11)
explicit exponential_distribution( const param_type& params ) ;
(3) (since C++11)

Constructs a new distribution object.

2) Uses lambda as the distribution parameter.
3) Uses params as the distribution parameter.

Parameters

lambda - the λ distribution parameter (the rate parameter)
params - the distribution parameter set

Notes

Requires that 0 < lambda.

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
P0935R0 C++11 default constructor was explicit made implicit