[fpc-pascal] Generic String Functions

[Sven Barth]

Am 28.02.2014 15:42, schrieb Michael Schnell:
> On 02/28/2014 03:00 PM, Sven Barth wrote:
>> As long as not stated differently AnsiString and UnicodeString are 
>> meant as implemented in FPC trunk.
> Can you point me to a _final_ documentation on this ?
Work on final documentation will be started when 2.8/3.0 will be 
released. Till then wiki.freepascal.org/FPC_Unicode_Support can be 
considered the documentation. Please note that the non existance of a 
documentation does not mean that a feature is not considered final. And 
the new string type is working as it should, what's still left is to 
adjust the RTL for more Ansi-/UnicodeString awareness.
> Of course I know how this works (otherwise this discussion would not 
> make any sense at all) that the implementation of the string record 
> allows for this, but Embarcadero does not allow the users to decently 
> take advantage of it.
>  - "non-Raw" does not allow for modifying the type and code-length fields
Yes, but you can always do it by converting to RawByteString:

=== code begin ===

function ChangeCodePage(aStr: RawByteString; aCodePage: 
TSystemCodePage): RawByteString;
begin
   Result := aStr;
   SetCodePage(Result, aCodePage, False);
end;

var
   s: UTF8String;
begin
   s := 'Hello World';
   Writeln(StringCodePage(s));
   s := ChangeCodePage(s, CP_ACP);
   Writeln(StringCodePage(s));
end.

=== code end ===

=== output begin ===

65001
0

=== output end ===

Regards,
Sven