Re: Empty String confusion; Positive and Natural

[Simon Wright <simon@pushface.org>]

Kevin Chadwick <kevc3no4@gmail.com> writes:

>> It would clarify your question if you would show the declaration of
>> that record type. Does it use the String type, or the
>> Unbounded_String type?
>
> Hopefully I will have a doh moment when I get into the office in the
> morning and post code. I am getting a range check exception when I
> assign "" to a standard.String in a record by returning the record
> from a function. Surely, I must have caused it somehow.

If you declare S : String (1 .. 5) and you want to assign a string "foo"
to the whole of S you are forbidden to do so by the language: you have
to assign 5 characters, no more, no fewer.

This can be a royal pain, so we have Ada.Strings.Bounded (if you know
the maximum length) or .Unbounded (if you don't, and can afford more
overhead), both of which support variable-length strings.