Re: Can I overload ":="?

[dog.ee.lbl.gov!hellgate.utah.edu!caen!destroyer!cs.ubc.ca!utcsri!torn!csd .unb.ca!morgan.ucs.mun.ca!nstn.ns.ca!mmaccorm@ucbvax.Berkeley.EDU (Mike Mac Co]

In article <1992Oct13.120715.7253@sei.cmu.edu> firth@sei.cmu.edu (Robert Firth)
 writes:
>In article <1992Oct12.194719.27071@fcom.cc.utah.edu> val@news.ccutah.edu (Val 
Kartchner) writes:

>>I would like to define what happens when I assign a value of one type (say
>>complex) to a variable of another type (say real).  Can I change what is
>>meant in Ada by the operation ":=" like I can do with the other operators,
>>or am I stuck with assignment of a type to a variable of that type?

>The direct answer is you can't do it: assignment works only between a
>value and a variable of the same type, and you can't redefine or
>overload the ":=" operation.

>The indirect answer is that you can define a type transfer function
>as anything you please, eg

>       function Convert (x:Chipmunk) return Integer;

>and then say

>       line_length := Convert(Dale);

>And, of course, you can overload Convert on any parameter and result type,
>so need choose only one name for all type conversion functions.  Jean
>Ichbiah's suggestion (with which I do not agree!) is that you use the
>unary "+" operator for type conversion.



Couldn't you use the type name as type conversion operator?  If you had a 
type "Complex", and wanted to convert it to a real, couldn't you 
overload "real" as follows:

	function real(c :Complex) return real;

and then use the statement

	r := real(c);

to convert it to a real?


	
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