[fpc-pascal] Documentation, syntax diagrams

[Constantine Yannakopoulos]

On Thu, Jan 9, 2014 at 9:55 AM, Sven Barth <pascaldragon at googlemail.com>wrote:

> Am 08.01.2014 22:01, schrieb Michael Van Canneyt:
>
>  You can preview the result at
>>
>> http://www.freepascal.org/~michael/ref/refch3.html
>>
> You might additionally mention that these type aliases also allow
> different operator and (AFAIK also) function overloads.
>

Also, that they have different RTTI records, that is the TypeInfo()
compiler function returns different pointers for the original and derived
type, while for simple type aliases (no "type" after "=") it returns the
same pointer.

In Delphi and I suppose in Lazarus this is often used in order to register
a specific property editor for each property of an otherwise common type
that has special semantics, e.g.

type
  TFileName = type string;

--
Constantine
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