#ifndef _unary_h

 #define _unary_h

 #include <cmath>

 #include <cfloat>

 #include <functional>    //*TY 12/26/1998 - added to get unary_function

 #if !defined (STLPORT) || defined (_STLP_USE_NAMESPACES)

 using std::unary_function;

 #endif

 struct odd : public unary_function<int, bool>

 {

 //  odd() {}

   bool operator()(int n_) const { return(n_ % 2) == 1; }

 };

 struct positive : public unary_function<int, bool>

 {

   typedef int argument_type;

   typedef bool result_type;

 //  positive() {}

   bool operator()(int n_) const { return n_ >= 0; }

 };

 struct square_root : public unary_function<double, double>

 {

   typedef double argument_type;

   typedef double result_type;

   square_root() {}

   square_root(const square_root &) {}

   double operator()(double x_) const

   { return ::sqrt(x_); }

 };

 #endif // _unary_h