From cppreference.com
param_typeparam()const; (1) (since C++11)voidparam(constparam_type¶ms); (2) (since C++11)Manages the associated distribution parameter set.
1) Returns the associated parameter set.
2) Sets the associated parameter set to params.
Parameters
params - new contents of the associated parameter set Return value
1) The associated parameter set.
2) (none)
Complexity
Constant.