[Lazarus] UTF8String and UTF8Delete

[Sven Barth]

On 12.12.2015 17:37, Jürgen Hestermann wrote:
> Is it correct that now every ansistring has a static code page
> and a dynamic code page (as mentioned in
> http://wiki.freepascal.org/FPC_Unicode_support)?

Yes.

>
> Is it correct that each ansistring type can store strings with any
> encoding (dynamic code page) but there is a "genuine" (static) code
> page which is preferred (in cases a target encoding needs to be chosen)?

Yes.

> What is the difference between
>
> UTF8String = type ansistring(cp_UTF8);
>
> and
>
> String = type ansistring(cp_ACP);
> when cp_ACP=cp_UTF8?

CP_ACP is *never* CP_UTF8. It is *always* CP_ACP. So these two will 
*always* be different types. However the specific codepage that CP_ACP 
refers to is determined at runtime and that can indeed be CP_UTF8.

>
> Both would have the same static code page (UTF-8) but may contain
> a different encoding at run time. So why can't I use an UTF8String
> in the same way as a String type as parameter?
> Why are they not assignment compatible?

They are assignment compatible (all AnsiStrings are) and the compiler 
will insert a code page conversion if necessary (if CP_ACP refers to 
CP_UTF8 and if one of the two strings is CP_ACP the other CP_UTF8 then 
the conversion routine won't do a code page conversion of course). 
However since they are different types you can't simply pass a 
AnsiString(CP_UTF8) to a var parameter of type AnsiString(CP_ACP).

Regards,
Sven