[fpc-pascal] Is it possible to redefine FreePascal types?

Howard Page-Clark hdpc at talktalk.net
Wed Nov 21 21:04:47 CET 2012

On 21/11/12 7:49, Kenneth Cochran wrote:
> Yes.
> type newString = type string;
> Any function that accepts newString as a parameter will cause a
> compilation error if you try to pass a normal string. You'll have to
> cast it to newString first.

This is not the case, as the following program demonstrates. The 
compiler does not even blink.

program Project1;

{$mode objfpc}{$H+}

type TnewString = type string;

function NewStringFn(ns: TnewString): integer;
var c: Char;
   Result := 0;
   for c in ns do
    if (c<>#0) then inc(Result);

var s:string = 'ansistring';
     ns:TnewString = 'new string';
   writeln('The new string length is ',NewStringFn(ns));
   writeln('The old string length is ',NewStringFn(s));

More information about the fpc-pascal mailing list