id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
13613	gcd performs modulo by zero which is undefined	James E. King, III	Daryle Walker	"Boost.Rational uses Boost.Integer's gcd method.  I Added Coverity Scan support to the Boost.Rational build and it identified an issue that needs investigation:

 	
CID 293013 (#4-12 of 12): Division or modulo by zero (DIVIDE_BY_ZERO)
divide_by_zero: In function call gcd, modulo by expression 0 has undefined behavior. [hide details]

(rational_test.cpp)
470    BOOST_CHECK_EQUAL( boost::gcd<T>(  0,  -9), static_cast<T>( 9) );

(rational.hpp)
IntType gcd(IntType n, IntType m)
{
    // Defer to the version in Boost.Integer

>   1. divide_arg: n is used as a divisor in function gcd.
    return integer::gcd( n, m );
}
"	Bugs	new	To Be Determined	integer	Boost 1.67.0	Problem		ub