[Boost-users] [STL] Is there a std::abs<>() function?

21 Dec 2008

      Hello,

It's strange to me that there seems not to be a  std::abs<>() function
in STL, with it I can write code like this:

double d = std::abs(-1.0);
int i = std::abs(-1);

Does anybody else have the same feeling?

Being uncomfortable with the abcence of it, I've wrote my own version
in my namespace:

#include <boost/utility/value_init.hpp>

// my abs function
// it works not only for POD types, but also for
// user types that are default constructible and
// support operator<() and unary operator-()
template<class T> T abs(const T & x)
{ 
    static boost::value_initialized<T> zero;
    return (x < zero? -x : x);
}

Thanks for any information.

Best regards
Max

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