From: Victor A. Wagner Jr. (vawjr_at_[hidden])
Date: 2004-05-15 08:10:37
what is >> expected to do if the number input it "out of range"?
can we, for example, write cin >> month; (see below for definition of month)?
should this be using numeric_limits<T>::epsilon() (instead of DBL_EPSILON)
and would that even work for numbers larger than 2.0?
At Friday 2004-05-14 14:08, you wrote:
>There has been some discussion previously on this list for a ranged type. My
>personal desire was to have new double types in the ranges [0.0, 1.0) and
>[0.0, 1.0] among other things. There are several other uses that I can
>imagine. Feel free to rip this apart or do whatever you want.
>
>#include <float.h>
>#include <assert.h>
>
>namespace boost
>{
> // a simple range class
> template<class policy>
> class range {
> public:
> typedef range<policy> self;
> typedef typename policy::value value;
> range() : m(min()) { }
> range(const self& x) : m(x) { }
> range(const value& x) { m = rangeAssert(x); }
> static const value min() { return policy::min(); }
> static const value max() { return policy::max(); }
> operator value() { return m; }
> self& operator=(const self& x) { m = x; return *this; }
> self& operator=(const value& x) { m = rangeAssert(x); return *this; }
> const value& rangeAssert(const value& x) const { assert(x <= max());
>assert(x >= min()); return x; };
> private:
> value m;
> };
>
> // some range policies
> struct RangePolicyZeroToOne {
> typedef double value;
> static const value min() { return 0.0; };
> static const value max() { return 1.0; };
> };
>
> struct RangePolicyZeroToBelowOne {
> typedef double value;
> static const value min() { return 0.0; };
> static const value max() { return 1.0 - DBL_EPSILON; };
> };
>
> struct RangePolicyPercent {
> typedef double value;
> static const value min() { return 0.0; };
> static const value max() { return 100.0; };
> };
>
> struct RangePolicyDegrees {
> typedef double value;
> static const value min() { return 0.0; };
> static const value max() { return 360.0 - DBL_EPSILON; };
> };
>
> struct RangePolicyRadians {
> typedef double value;
> static const value min() { return 0.0; };
> static const value max() { return (2 * PI) - DBL_EPSILON; };
> };
>
> template <typename T, T min_T, T max_T>
> struct StaticRange {
> typedef T value;
> static const value min() { return min_T; };
> static const value max() { return max_T; };
> }
>
> // some sample types made with ranges
> typedef range<RangePolicyZeroToOne> Probability;
> typedef range<RangePolicyZeroToBelowOne> Distribution;
> typedef range<RangePolicyPercent> Percent;
> typedef range<RangePolicyDegrees> Degrees;
> typedef range<RangePolicyRadians> Radians;
> typedef range<RangePolicyStatic<int, 0, 11> > Month;
> typedef range<RangePolicyStatic<int, 0, 364> > DayOfTheYear;
> typedef range<RangePolicyStatic<int, 0, 6> > DayOfTheWeek;
> typedef range<RangePolicyStatic<char, 'a', 'z'> > LowerCaseLetter;
> typedef range<RangePolicyStatic<char, 'A', 'Z'> > UpperCaseLetter;
> typedef range<RangePolicyStatic<char, '0', '9'> > NumberChar;
>};
>
>by Christopher Diggins
>licensed under the Boost software license
>
>http://www.cdiggins.com
>http://www.heron-language.com
>
>_______________________________________________
>Unsubscribe & other changes: http://listarchives.boost.org/mailman/listinfo.cgi/boost
Victor A. Wagner Jr. http://rudbek.com
The five most dangerous words in the English language:
"There oughta be a law"