• kerdemdemir (29/29) Dec 24 2017 In documentation and forums I found some example for overloading
• =?UTF-8?Q?Ali_=c3=87ehreli?= (7/8) Dec 24 2017 I can't answer your question but I know that the comparison above is
• drug (15/29) Dec 24 2017 I'd do something like that (disclaimer - from memory):
• drug (15/44) Dec 24 2017 should be

kerdemdemir <kerdemdemir gmail.com> writes:

In documentation and forums I found some example for overloading 
opCmp for int values. But I couldn't see any examples for double 
values.

That is what I come up with my own:

struct AdjustableVal ( T = double )
{
	this ( T initVal )
	{
		curVal = initVal;
		initialVal = initVal;
	}
	
	
     int opCmp( T rhs ) const {
         auto diff = curVal - rhs;
         if (  fabs(diff) < 0.00000001 )
             return 0;
         else if ( diff < 0 )
             return -1;
         else
             return 1;
      }

	T curVal;
	T initialVal;
}

Do you guys see any problem with it or any suggestions?
Secondly if the value type(T) does not have "-" operator, is it 
possible to still get my code compiled somehow with static_if?


Erdem

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 12/24/2017 02:10 AM, kerdemdemir wrote:

          if (  fabs(diff) < 0.00000001 )

I can't answer your question but I know that the comparison above is 
wrong because it can be meaningful only if the values are sufficiently 
larger than that hard-coded value.

I think feqrel() will be useful there:

   https://dlang.org/phobos/std_math.html#.feqrel

Ali

drug <drug2004 bk.ru> writes:

25.12.2017 09:50, Ali Çehreli пишет:
 On 12/24/2017 02:10 AM, kerdemdemir wrote:
 
  >          if (  fabs(diff) < 0.00000001 )
 
 I can't answer your question but I know that the comparison above is 
 wrong because it can be meaningful only if the values are sufficiently 
 larger than that hard-coded value.
 
 I think feqrel() will be useful there:
 
    https://dlang.org/phobos/std_math.html#.feqrel
 
 Ali
 

I'd do something like that (disclaimer - from memory):
```
     int opCmp( T rhs ) const {
         auto diff = curVal - rhs;
	auto epsilon = max(curVal.epsilon, rhs.epsilon);
         if (  fabs(diff) < epsilon )
             return 0;
         else if ( diff < 0 )
             return -1;
         else
             return 1;
     }
```
so in this case epsilon is also floating.

drug <drug2004 bk.ru> writes:

25.12.2017 10:40, drug пишет:
 25.12.2017 09:50, Ali Çehreli пишет:
 On 12/24/2017 02:10 AM, kerdemdemir wrote:

  >          if (  fabs(diff) < 0.00000001 )

 I can't answer your question but I know that the comparison above is 
 wrong because it can be meaningful only if the values are sufficiently 
 larger than that hard-coded value.

 I think feqrel() will be useful there:

    https://dlang.org/phobos/std_math.html#.feqrel

 Ali

 I'd do something like that (disclaimer - from memory):
 ```
      int opCmp( T rhs ) const {
          auto diff = curVal - rhs;
      auto epsilon = max(curVal.epsilon, rhs.epsilon);
          if (  fabs(diff) < epsilon )
              return 0;
          else if ( diff < 0 )
              return -1;
          else
              return 1;
      }
 ```
 so in this case epsilon is also floating.

should be
  ```
       int opCmp( T rhs ) const {
           auto diff = curVal - rhs;
           // get error for curVal and rhs
           auto epsilon = max(curVal.epsilon * curVal, rhs.epsilon * rhs);
           if (  fabs(diff) < epsilon )
               return 0;
           else if ( diff < 0 )
               return -1;
           else
               return 1;
       }
  ```