Questions on OOP in MQL5 - page 92

[Igor Makanu]

Vladimir Simakov:

int CSetting::sign=1<<31;
int CSetting::_sign=1<<11;
int CSetting::mean=0xFFFFFFFF>>21;

YES!

I never would have guessed that variable values can be set by the necessary shift !

cool! thanks!

[Dmitry Fedoseev]

With complete economy of space:

void OnStart()
{

   int a=2; // 0,1,2
   int b=7; // 0,1,2
   int c=7; // 0,1,2,3,4,5,6,7
   int d=12345;  
   
   int v=a+b*3+c*(3*8)+d*(3*8*8);
   
   d=v/(3*8*8);
   v%=(3*8*8);
   
   c=v/(3*8);
   v%=(3*8);   
   
   b=v/3;
   a%=3;     
   
   Alert(a," ",b," ",c," ",d);
  
} 

[Igor Makanu]

Vladimir Simakov:

another question... Is there any way to get a 12 bit int via union ?... never mind how ))))

ZS: ideally a 9-15 bit int , the sign is not a problem, i.e. it is possible to unsigned int (in the last builds MQL has learnedunsigned int, it is possible to use instead of uint )

[Dmitry Fedoseev]

Icho:

void OnStart()
{
   int a=2; // 0,1,2
   int b=3; // 0,1,2
   int c=7; // 0,1,2,3,4,5,6,7
   int d=12345;  

   int v=(d<<8)|(c<<5)|(b<<2)|a;
   
   a=v&3;
   v>>=2;
   b=v&7;
   v>>=3;   
   c=v&7;  
   v>>=3;      
   d=v;
   
   Alert(a," ",b," ",c," ",d);

}

[Dmitry Fedoseev]

Igor Makanu:

another question... Is there any way to get a 12 bit int via union ?... never mind how ))))

ZS: 9-15 bit int ideally , the sign to allocate is not a problem, i.e. it is possible unsigned int (in last builds MQL has learnedunsigned int, it is possible instead of uint to use )

Probably not. There are no half byte variables yet.

[Igor Makanu]

Dmitry Fedoseev:

Probably not. There are no half bytes of variables yet.

Why not? Encode and mask the required bits, any number of bits can be used

but the problem is not to screw it up ;)

UPD: googling such a question, at least read what they advisehttps://stackoverflow.com/questions/29529979/10-or-12-bit-field-data-type-in-c

[Dmitry Fedoseev]

Igor Makanu:

Why not? encode and mask the required bits, any number of bits can be used

but the problem is not to screw it up ;)

Then you can do without union too.

[Igor Makanu]

Dmitry Fedoseev:

Then you can do without the union, too.

yes, union is more of a problem than a convenience

[[Deleted]]

Any idea why the compiler uses the method in the base-class?

[Dmitry Fedoseev]

Nelson Wanyama:

Any idea why the compiler uses the method in the base-class?

Because you are not overriding a virtual function, you are using overloading.