[boost] bug in random_number_generator ?

From: David J. Pearce (d.pearce_at_[hidden])
Date: 2003-03-05 04:09:49

Hello,

I believe there is bug in random_number_generator when you request a 
random number between 0 and 1. For example:

 > random_number_generator rgen(...);
 > cout << rgen(1) << endl; // causes assertion failure

I encountered this problem when using random_number_generator in 
conjuction with the random_sample_n algorithm.
I have attached a simple patch which catches the case when the parameter 
is 1. If anyone can tell me whether this is a reasonable fix, I would be 
grateful.

Thanks,

David J. Pearce


*** random_number_generator.old	2003-02-25 16:41:26.000000000 +0000
--- random_number_generator.hpp	2003-02-25 16:42:00.000000000 +0000
***************
*** 50,56 ****
    // assignment is disallowed because there is a reference member
  
    result_type operator()(argument_type n) {
!     return uniform_int<base_type>(_rng, 0, n-1)();
    }
  
  private:
--- 50,60 ----
    // assignment is disallowed because there is a reference member
  
    result_type operator()(argument_type n) {
!     if(n == 1) { 
!       return 0;
!     } else {
!       return uniform_int<base_type>(_rng, 0, n-1)();
!     }
    }
  
  private: