Re: Need of help Leonid(dulman@ibm.net)

[kst@aonix.com (Keith Thompson)]

In <3302387F.16BB@mds.lmco.com> Rex Reges <reges@mds.lmco.com> writes:
[...]
> An interesting problem occurred while trying to provide the 
> utility functions.  I had the following function:
> 
> function V_String_Of( Standard_String : in   String )
>          return                            V_String is
> begin
> 
>    -- Test omitted for Strings that are too large to fit.
> 
>    return ( Size => Standard_String'Length ,
>             S    => Standard_String        ) ;
> 
> end V_String_Of ;
> 
> 
> I liked this code because it did not require creating a 
> temporary variable on the stack, particularly if the string
> was very large.  However, it failed whenever a substring
> was passed which had a starting index other than 1:
[...]

Try this:

   function V_String_Of( Standard_String : in   String )
            return                            V_String is
      subtype Constrained_Result is String(1 .. Standard_String'Length);
   begin
    
      -- Test omitted for Strings that are too large to fit.
    
      return ( Size => Standard_String'Length ,
               S    => Constrained_Result(Standard_String) );
    
   end V_String_Of;

Note that the expression for S has to be a conversion, not a qualified
expression.

-- 
Keith Thompson (The_Other_Keith) kst@aonix.com <http://www.aonix.com> <*>
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