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From: David Abrahams (dave_at_[hidden])
Date: 2003-02-25 07:44:11

Michael Stevens <Michael.Stevens_at_[hidden]> writes:

> 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.


Could you please suggest a patch for the regression tests which will
detect this problem? It's always better to get the test to fail
first before we check in any fixes.


Dave Abrahams
Boost Consulting

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