无符号双人

Question

我需要使用unsigned double,但事实证明C#不提供这样的类型.

有谁知道为什么？

Answer 1

浮点数只是IEEE 754规范的实现.据我所知,在那里没有无符号的双子.

http://en.wikipedia.org/wiki/IEEE_754-2008

为什么需要无符号浮点数？

Answer 2

正如Anders Forsgren所指出的那样,IEEE规范中没有未签名的双精度数据(因此不在C#中).

您可以通过调用Math.Abs​​()来获得正值,并且可以在结构中包含double并在那里强制执行约束:

public struct PositiveDouble 
{
      private double _value;
      public PositiveDouble() {}
      public PositiveDouble(double val) 
      {
          // or truncate/take Abs value automatically?
          if (val < 0)
              throw new ArgumentException("Value needs to be positive");
          _value = val;
      }

      // This conversion is safe, we can make it implicit
      public static implicit operator double(PositiveDouble d)
      {
          return d._value;
      }
      // This conversion is not always safe, so we make it explicit
      public static explicit operator PositiveDouble(double d)
      {
          // or truncate/take Abs value automatically?
          if (d < 0)
              throw new ArgumentOutOfRangeException("Only positive values allowed");
          return new PositiveDouble(d);
      }
      // add more cast operators if needed
}