[boost] [random] Minor problem with lognormal_distribution

From: Michael Stevens (Michael.Stevens_at_[hidden])
Date: 2003-02-25 04:49:10

Dear Boosters,

This is just a quick reminder of regression before boost_1_30_0 gets 
released. Without CVS access I can fix it myself and Jens seems to be 
offline at the moment. It would be great if someone could step in and 
make a simple correction.

The regression is the the return values of the mean and sigma values of 
boost::random::lognormal_distribution.

Correction required for boost/random/lognormal_distribution. hpp line 67-68

RealType& mean() const { return _mean; }
RealType& sigma() const { return _sigma; }

should read.

RealType mean() const { return _mean; }
RealType sigma() const { return _sigma; }

The correction makes the return values identical with those of other 
real distributions, cf. normal_distribution line 62

The problem can simply be tested by instantiating the template thus
template boost::normal_distribution<boost::mt19937, float>;

It should be noted that the problem is NOT picked up by regression tests 
in random_test.cpp. The current test procedure
void instantiate_dist(const char * name, const Dist& dist)
uses a reference to a constant distribution. It therefore fails to 
pickup on the return of non constant member reference.

All the best,

Michael Stevens