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copied!<p>When <a href="http://docs.embarcadero.com/products/rad_studio/delphiAndcpp2009/HelpUpdate2/EN/html/devcommon/compdirstypecheckedpointers_xml.html" rel="nofollow noreferrer">typed @ operator</a> is off the compiler does not check what you assign to a pointer, so you can call a procedure with <em>wrong</em> parameters:</p> <pre><code>program Project1; {$APPTYPE CONSOLE} type TCharArray = array of Char; procedure DoArray(Chars: array of Char); begin end; function ReturnTCharArray: TCharArray; var CharArray: TCharArray; begin Result := CharArray; end; type TFakeDoArray = procedure(Chars: TCharArray); var FakeDoArray: TFakeDoArray; begin FakeDoArray := @DoArray; FakeDoArray(ReturnTCharArray); end. </code></pre> <p>While the compiler won't complain, for the very reason 'Jeroen' indicates in his comment for <a href="https://stackoverflow.com/questions/3780235/delphi-array-of-char-and-tchararray-incompatible-types/3780279#3780279">Mason's answer</a>, this will not work.</p> <p>You can then try declaring your fake procedure compatible with one with an open array parameter:</p> <pre><code>program Project1; {$APPTYPE CONSOLE} type TCharArray = array of Char; procedure DoArray(Chars: array of Char); begin end; function ReturnTCharArray: TCharArray; var CharArray: TCharArray; begin Result := CharArray; end; type TFakeDoArray = procedure(AnArray: Pointer; High: Integer); var FakeDoArray: TFakeDoArray; Tmp: TCharArray; begin FakeDoArray := @DoArray; Tmp := ReturnTCharArray; FakeDoArray(Tmp, High(Tmp)); end. </code></pre> <p>Credits are due Rudy for his <a href="http://rvelthuis.de/articles/articles-openarr.html" rel="nofollow noreferrer">great article</a>. And the relevant documentation (from <a href="http://docs.embarcadero.com/products/rad_studio/radstudio2007/RS2007_helpupdates/HUpdate4/EN/html/devcommon/programcontrolov_xml.html#50617373696E6720506172616D6574657273" rel="nofollow noreferrer">Program Control</a>):</p> <blockquote> <p>An open-array parameter is passed as two 32-bit values. The first value is a pointer to the array data, and the second value is one less than the number of elements in the array.</p> </blockquote>

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