Re: U : Unbounded String : "bla bla bla"; (was: Is the Writing...)

[aek@vib.usr.pu.ru (Alexander Kopilovitch)]

amado.alves wrote:

> User-defined implicit conversion would solve this problem. Pragma 
> approach:
> 
>   function To Unbounded (S : String) return Unbounded String;
>   pragma Implicit Conversion (To Unbounded);
>   U : Unbounded String := "bla bla bla";

Implicit conversions lead to some problems (it is also known from C++ experience.)
I'm sure that it would be serious mistake to add implicit conversions to the
language for purposes of this rank only. Generally, I think that implicit
conversion are significantly less compatible with Ada spirit than with C++
spirit; in C++ implicit conversions probably do more good than bad, while in
Ada they probably will do more bad than good.

> However it is too late for Ada 2005 now :-(

Well, I think that for unclear and disputable issues (like this) we should not
pay attention to the deadlines -:) . If we find a good solution, which pleases
both users and compiler vendors then probably ARG will be happy to include it 
into some Technical Corrigendum -:) .



Alexander Kopilovitch                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia