Hi Johannes, On Mon, 13 Oct 2008 13:12:02 +0200, "Johannes Brunen" <JBrunen@DataSolid.de> said:
Hello Andy,
after some investigations, I think that I have found the origin of the problem:
In seed_rng.hpp the following code is used:
template <typename UniformRandomNumberGenerator> inline void seed(UniformRandomNumberGenerator& rng) { seed_rng seed_gen; boost::generator_iterator<seed_rng> begin(&seed_gen); boost::generator_iterator<seed_rng> end; rng.seed(begin, end); }
Problematic is the construction of the end iterator. Looking into the code (boost/generator_iterator.hpp) shows, that the default constructor of generator_iterator does not initialize its member variables.
generator_iterator() {}
Howerver, the mersenne_twister seed code does compare the two given iterators as shown below (boost/random/).
template<class It> void seed(It& first, It last) { int j; for(j = 0; j < n && first != last; ++j, ++first) x[j] = *first; i = n; if(first == last && j < n) throw std::invalid_argument("mersenne_twister::seed"); }
As the end iterator is not initialized the way is open for all throwing the invalid_argument exception.
Locally, I did solve the problem by patching the default constructor of class generator_iterator.
If this is a valid solution of the problem, it would be fine if anyone applies the correction to the boost code.
Greetings, Johannes
I have put a new version in the boost vault. http://www.boostpro.com/vault/index.php?action=downloadfile&filename=uuid_v13.zip&directory=& It addresses this problem by making a copy of boost::generator_iterator with your fix. Regards, Andy.