comparison DEPENDENCIES/generic/include/boost/date_time/wrapping_int.hpp @ 16:2665513ce2d3

Add boost headers

+#ifndef _DATE_TIME_WRAPPING_INT_HPP__
+#define _DATE_TIME_WRAPPING_INT_HPP__
+
+/* Copyright (c) 2002,2003,2005 CrystalClear Software, Inc.
+ * Use, modification and distribution is subject to the
+ * Boost Software License, Version 1.0. (See accompanying
+ * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
+ * Author: Jeff Garland, Bart Garst
+ * $Date: 2012-09-22 15:33:33 -0700 (Sat, 22 Sep 2012) $
+ */
+
+
+namespace boost {
+namespace date_time {
+
+//! A wrapping integer used to support time durations (WARNING: only instantiate with a signed type)
+/*! In composite date and time types this type is used to
+ *  wrap at the day boundary.
+ *  Ex:
+ *  A wrapping_int<short, 10> will roll over after nine, and
+ *  roll under below zero. This gives a range of [0,9]
+ *
+ * NOTE: it is strongly recommended that wrapping_int2 be used
+ * instead of wrapping_int as wrapping_int is to be depricated
+ * at some point soon.
+ *
+ * Also Note that warnings will occur if instantiated with an
+ * unsigned type. Only a signed type should be used!
+ */
+template<typename int_type_, int_type_ wrap_val>
+class wrapping_int {
+public:
+  typedef int_type_ int_type;
+  //typedef overflow_type_ overflow_type;
+  static int_type wrap_value() {return wrap_val;}
+  //!Add, return true if wrapped
+  wrapping_int(int_type v) : value_(v) {}
+  //! Explicit converion method
+  int_type as_int()   const   {return value_;}
+  operator int_type() const   {return value_;}
+  //!Add, return number of wraps performed
+  /*! The sign of the returned value will indicate which direction the
+   * wraps went. Ex: add a negative number and wrapping under could occur,
+   * this would be indicated by a negative return value. If wrapping over
+   * took place, a positive value would be returned */
+  template< typename IntT >
+  IntT add(IntT v)
+  {
+    int_type remainder = static_cast<int_type>(v % (wrap_val));
+    IntT overflow = static_cast<IntT>(v / (wrap_val));
+    value_ = static_cast<int_type>(value_ + remainder);
+    return calculate_wrap(overflow);
+  }
+  //! Subtract will return '+d' if wrapping under took place ('d' is the number of wraps)
+  /*! The sign of the returned value will indicate which direction the
+   * wraps went (positive indicates wrap under, negative indicates wrap over).
+   * Ex: subtract a negative number and wrapping over could
+   * occur, this would be indicated by a negative return value. If
+   * wrapping under took place, a positive value would be returned. */
+  template< typename IntT >
+  IntT subtract(IntT v)
+  {
+    int_type remainder = static_cast<int_type>(v % (wrap_val));
+    IntT underflow = static_cast<IntT>(-(v / (wrap_val)));
+    value_ = static_cast<int_type>(value_ - remainder);
+    return calculate_wrap(underflow) * -1;
+  }
+private:
+  int_type value_;
+
+  template< typename IntT >
+  IntT calculate_wrap(IntT wrap)
+  {
+    if ((value_) >= wrap_val)
+    {
+      ++wrap;
+      value_ -= (wrap_val);
+    }
+    else if(value_ < 0)
+    {
+      --wrap;
+      value_ += (wrap_val);
+    }
+    return wrap;
+  }
+
+};
+
+
+//! A wrapping integer used to wrap around at the top (WARNING: only instantiate with a signed type)
+/*! Bad name, quick impl to fix a bug -- fix later!!
+ *  This allows the wrap to restart at a value other than 0.
+ */
+template<typename int_type_, int_type_ wrap_min, int_type_ wrap_max>
+class wrapping_int2 {
+public:
+  typedef int_type_ int_type;
+  static int_type wrap_value() {return wrap_max;}
+  static int_type min_value()  {return wrap_min;}
+  /*! If initializing value is out of range of [wrap_min, wrap_max],
+   * value will be initialized to closest of min or max */
+  wrapping_int2(int_type v) : value_(v) {
+    if(value_ < wrap_min)
+    {
+      value_ = wrap_min;
+    }
+    if(value_ > wrap_max)
+    {
+      value_ = wrap_max;
+    }
+  }
+  //! Explicit converion method
+  int_type as_int()   const   {return value_;}
+  operator int_type() const {return value_;}
+  //!Add, return number of wraps performed
+  /*! The sign of the returned value will indicate which direction the
+   * wraps went. Ex: add a negative number and wrapping under could occur,
+   * this would be indicated by a negative return value. If wrapping over
+   * took place, a positive value would be returned */
+  template< typename IntT >
+  IntT add(IntT v)
+  {
+    int_type remainder = static_cast<int_type>(v % (wrap_max - wrap_min + 1));
+    IntT overflow = static_cast<IntT>(v / (wrap_max - wrap_min + 1));
+    value_ = static_cast<int_type>(value_ + remainder);
+    return calculate_wrap(overflow);
+  }
+  //! Subtract will return '-d' if wrapping under took place ('d' is the number of wraps)
+  /*! The sign of the returned value will indicate which direction the
+   * wraps went. Ex: subtract a negative number and wrapping over could
+   * occur, this would be indicated by a positive return value. If
+   * wrapping under took place, a negative value would be returned */
+  template< typename IntT >
+  IntT subtract(IntT v)
+  {
+    int_type remainder = static_cast<int_type>(v % (wrap_max - wrap_min + 1));
+    IntT underflow = static_cast<IntT>(-(v / (wrap_max - wrap_min + 1)));
+    value_ = static_cast<int_type>(value_ - remainder);
+    return calculate_wrap(underflow);
+  }
+
+private:
+  int_type value_;
+
+  template< typename IntT >
+  IntT calculate_wrap(IntT wrap)
+  {
+    if ((value_) > wrap_max)
+    {
+      ++wrap;
+      value_ -= (wrap_max - wrap_min + 1);
+    }
+    else if((value_) < wrap_min)
+    {
+      --wrap;
+      value_ += (wrap_max - wrap_min + 1);
+    }
+    return wrap;
+  }
+};
+
+
+
+} } //namespace date_time
+
+
+
+#endif
+