Re: Negative float problem

[Maciej Sobczak <no.spam@no.spam.com>]

Dmitry A. Kazakov wrote:

>>>Further, parameterless function call is
>>>indistinguishable from name.
>>
>>So? ADL is about *arguments* and does not apply to parameterless 
>>functions at all.
> 
> But in A.B.C (argument) you do not know whether B is a package, function
> name or variable.

ADL applies only to unqualified names.
The above example does not explain why Ada does not have ADL, because it 
is not more complicated than what is there in C++ anyway - in 
particular, with overloaded function call operators and overloaded 
dereference operators the expression A.B->C(argument) may have many 
meanings as well and I don't see in what way Ada represents a more 
general case here.
The important thing is that ADL is *not* used in such cases.

Let's consider again the original problem stated in this thread. The 
operator name is unqualified and finding it in the namespace (package) 
associated with its argument is not a rocket science. It is what the 
programmer expects.

> Some legal code might become illegal, because some invisible before
> operations would contribute to overloading.

Could you please give an example of such code?

Remember that we're considering unqualified names. Note also that ADL is 
performed *only* when the normal lookup fails (it's an extension 
mechanism). This means that by adding ADL to the language you cannot 
break existing code - but you can make some code working that was not 
working before. For example the code from the beginning of this thread.


-- 
Maciej Sobczak : http://www.msobczak.com/
Programming    : http://www.msobczak.com/prog/