rationals initialization bug

From: John (EBo) David (ebo_at_[hidden])
Date: 2000-11-21 15:15:00

When playing with the rationals some more I ran across another bug.
When initializing a rational from a floating point number, the value
is auto-casted to IntType and produces erroneous results.  For
example:

    int main ()
    {
      rational <int> tr;
  
      td = 1.5; tr = td;
      std::cout << "rational " << tr;
      std::cout << " cast " << boost::rational_cast<double>(tr);
      std::cout << " original double " << td << std::endl;
    }

sets tr to be "1/1" and not "3/2"

Is it reasonable to provide a rational constructor and/or assignment
with a floating point argument?

Somewhat related to this is the operator>> definition.  Isn't it
reasonable to assume that the user defined input should not have to be
redefined to use the "nnn/ddd" syntax, but to behave as expected when
accepting floating point input? 

 EBo --