flower/include/real.hh

   1 /*
   2   real.hh -- declare Real
   3
   4   source file of the Flower Library
   5
   6   (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #ifndef REAL_HH
  10 #define REAL_HH
  11
  12 #include <algorithm>
  13 #include <climits>
  14 #include <cmath>
  15 using namespace std;
  16
  17 typedef double Real;
  18 extern const Real infinity_f;
  19
  20 /* namespace std { */
  21
  22 template<class T> inline T abs (T x)
  23 {
  24   return x > 0 ? x : -x;
  25 }
  26
  27 /* } namespace std */
  28
  29 inline Real
  30 distance (Real x, Real y)
  31 {
  32   return abs (x - y);
  33 }
  34
  35 template<class T> inline int sign (T x)
  36 {
  37   if (x)
  38     return x > T (0) ? 1 : -1;
  39   return 0;
  40 }
  41
  42 template<class T> inline T sqr (T x)
  43 {
  44   return x * x;
  45 }
  46
  47 #endif