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From: Eric Sosman <esosman@comcast-dot-net.invalid>
Newsgroups: comp.lang.java.programmer
Subject: Re: Can Java 8 do exact arithmetic as in C#
Date: Mon, 8 Jan 2018 08:42:50 -0500
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On 1/8/2018 7:21 AM, j4n bur53 wrote:
> The source code is available, its a pure Java
> implementation, no native code. For example addExact
> is implemented as follows:
> 
>      /**
>       * Returns the sum of its arguments,
>       * throwing an exception if the result overflows an {@code int}.
>       *
>       * @param x the first value
>       * @param y the second value
>       * @return the result
>       * @throws ArithmeticException if the result overflows an int
>       * @since 1.8
>       */
>      public static int addExact(int x, int y) {
>          int r = x + y;
>          // HD 2-12 Overflow iff both arguments
>          // have the opposite sign of the result
>          if (((x ^ r) & (y ^ r)) < 0) {
>              throw new ArithmeticException("integer overflow");
>          }
>          return r;
>      }
> 
> HD 2-12 probably means Handbook of ... (who knows?)
> chapter 2 section 12.

https://en.wikipedia.org/wiki/Hacker's_Delight

... would be my guess.

-- 
esosman@comcast-dot-net.invalid
Eleven hundred eight days to go.