Constarin Type Parameters As Numeric

[ghost]

I was writing this struct:

    struct Range<T > where T : struct, IComparable
    {
        T Min { get; set; }
        T Max { get; set; }

        public Range(T min, T max)
        {
            Min = min;
            Max = max;
            _value = min;
        }

        T _value;
        T Value
        {
            get => _value;

            set
            {
                if (value.CompareTo(Max) == 1 || value.CompareTo(Min) == -1)
                    throw new ArgumentOutOfRangeException();

                _value = value;
            }
        }


        public static implicit operator T(Range<T> r)
        {
            return r.Value;
        }
    }

I want to use this range to deal with basic numeric data types and dates. Why there is no keywords for:

• numeric constraint.
• integer constraint (byte, sbyte, int, uint, short, ushort, long, ulong)
• floating constraint (float, double, decemal)
• value constraint (numerics and dates).
• Letiral constraint(Char and string).
• primitive constraint (numerics, dates, char, string)?

These basic types have common behavior, but they have't a base class or interface.

[HaloFour]

Why does this struct need any such constraints? You're not performing any specialized arithmetic operations.

Also, DateTime wouldn't qualify as numeric, literal or primitive.

[ghost]

Why does this struct need any such constraints? You're not performing any specialized arithmetic operations.

A range means a sequnce of continuous values. It implies arithmetic increment, which applies to numeric, date and char types.

DateTime wouldn't qualify as numeric, literal or primitive.
It can make continuous range of dates. It is a numeric in this sense and date is reperesnted as double value.

[ghost]

besides, I needed this in the In-Range Data Types proposal #1198 .

[HaloFour]

@MohammadHamdyGhanem

A range means a sequnce of continuous values. It implies arithmetic increment, which applies to numeric types and dates.

A range implies comparability between values, nothing more. The potential continuous nature and lack of any universal unit makes arithmetic incrementing impossible.

It can make continuous range of dates. It is a numeric in this sense and date is reperesnted as double value.

A DateTime is represented internally by a ulong, not a double. And that ulong contains a bitmask flag indicating a type, which impacts that actual value of the DateTime. What is the unit of DateTime? Increment that 64-bit integer by 1 and you're moving the clock forward by 100 nanoseconds. That's very likely not what you intend when you "add one" to a date.

[HaloFour]

I'll note that a Range<T> struct is already under design and consideration by the BCL team, to complement the proposed/championed range operator feature:

System.Range.cs

[ghost]

There is a deeference. The you can rename my range as ConstrainedNumeric. If the can add a Value property to the Range Class, then both ideas can be combined togather, but my ConstrainedNumeric is lightweight structure sutable for basic data types.

[orthoxerox]

@MohammadHamdyGhanem you'll need shapes for the constraints you want.

[ghost]

@HaloFour , @orthoxerox
I posted a new proposal with a new approach:
#1387