regarding the quality of math functions in stl/boost

From: adam_speight (adam_speight_at_[hidden])
Date: 2003-03-23 13:00:41

I've often heard that you should never trust your system 
implementation of functions like sqrt, exp, sin, cos, rand, etc.  
Instead, most mathematicians say that one should use an 
implementation that is known to be accurate up to some order.  
Unfortunately, using third-party code for these functions hinders 
portability.

I know that boost has a formidable random number generation library 
that uses the cmath versions of basic math functions.  Does the stl 
standard, or various implementations of stl, make any gaurantees 
about the accuracy of these basic math functions?  Are they safe to 
use for mathematical applications in practice?

Thanks,

Adam