Editing Pointer (computer programming) (section)

===Pascal===
Unlike many languages that feature pointers, standard [[International Organization for Standardization|ISO]] [[Pascal (programming language)|Pascal]] only allows pointers to reference dynamically created variables that are anonymous and does not allow them to reference standard static or local variables.<ref>ISO 7185 Pascal Standard (unofficial copy), section [http://standardpascal.org/iso7185.html#6.4.4%20Pointer-types 6.4.4 Pointer-types] {{Webarchive|url=https://web.archive.org/web/20170424183023/http://www.standardpascal.org/iso7185.html#6.4.4%20Pointer-types |date=2017-04-24}} and subsequent.</ref> It does not have pointer arithmetic. Pointers also must have an associated type and a pointer to one type is not compatible with a pointer to another type (e.g. a pointer to a char is not compatible with a pointer to an integer). This helps eliminate the type security issues inherent with other pointer implementations, particularly those used for [[PL/I]] or [[C (Programming Language)|C]]. It also removes some risks caused by [[dangling pointers]], but the ability to dynamically let go of referenced space by using the <code>dispose</code> standard procedure (which has the same effect as the <code>free</code> library function found in [[C (Programming Language)|C]]) means that the risk of dangling pointers has not been entirely eliminated.<ref>J. Welsh, W. J. Sneeringer, and C. A. R. Hoare, "Ambiguities and Insecurities in Pascal," ''Software: Practice and Experience 7'', pp. 685–696 (1977)</ref>

However, in some commercial and open source Pascal (or derivatives) compiler implementations —like [[Free Pascal]],<ref>Free Pascal Language Reference guide, section [http://www.freepascal.org/docs-html/ref/refse15.html#x43-490003.4 3.4 Pointers]</ref> [[Turbo Pascal]] or the [[Object Pascal]] in [[Embarcadero Delphi]]— a pointer is allowed to reference standard static or local variables and can be cast from one pointer type to another. Moreover, pointer arithmetic is unrestricted: adding or subtracting from a pointer moves it by that number of bytes in either direction, but using the <code>Inc</code> or <code>Dec</code> standard procedures with it moves the pointer by the size of the [[data type]] it is ''declared'' to point to. An untyped pointer is also provided under the name <code>Pointer</code>, which is compatible with other pointer types.