std::normal_distribution::mean, stddev
From cppreference.com
                    
                                        
                    < cpplrm; | numericlrm; | randomlrm; | normal distribution
                    
                                                            
                    | RealType mean() const; | (1) | (since C++11) | 
| RealType stddev() const; | (2) | (since C++11) | 
Returns the parameters the distribution was constructed with.
1) Returns the mean  distribution parameter. The mean specifies the location of the peak. The default value is 0.0.
2) Returns the deviation  distribution parameter. The default value is 1.0.
Parameters
(none)
Return value
1) The mean  distribution parameter.
2) The deviation  distribution parameter.
See also
| gets or sets the distribution parameter object (public member function) |