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digitalmars.D - Inconsistency increasing

reply DavidL <Davidl 126.com> writes:
opAdd_r VS opAdd
opImpicitCastTo VS opImplicitCastFrom

consider:
objectA + objectB

objectB get opAdd_r
objectA get opAdd

what would happen?

structB = structA
structA get opImplicitCastTo and structB get opImplicitCastFrom, what  
would happen?
both get called? or the one *well* defined by compiler( this kind of  
specification could cause
many issues imo)

we don't need an OOP style operator overloading
we need a global operator overloading


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Aug 26 2007
parent "Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:
"DavidL" <Davidl 126.com> wrote in message 
news:op.txn9lnubbag506 39eee18d1a25413...

 opAdd_r VS opAdd
 opImpicitCastTo VS opImplicitCastFrom

 consider:
 objectA + objectB

 objectB get opAdd_r
 objectA get opAdd

 what would happen?


This is already defined.  See 
http://www.digitalmars.com/d/1.0/operatoroverloading.html, Binary Operator 
Overloading, example 5.  This is ambiguous.


 structB = structA
 structA get opImplicitCastTo and structB get opImplicitCastFrom, what 
 would happen?
 both get called? or the one *well* defined by compiler( this kind of 
 specification could cause
 many issues imo)


This would probably result in a similar ambiguosity.


 we don't need an OOP style operator overloading
 we need a global operator overloading


If it's well-defined (which it is), OOP-style operator overloading works 
just fine.  However, notice that D2 is generalizing method calls, so that 
"x.f()" and "f(x)" can be semantically equivalent.  This might bring global 
operator overloading as a side-effect.
Aug 26 2007