Function pointer - Revision history

Peter Flass: /* PL/I */ changes per talk comment.

2025-04-06T03:06:47Z

PL/I: changes per talk comment.

← Previous revision		Revision as of 03:06, 6 April 2025
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	==PL/I==		==PL/I==
	[[PL/I]] procedures can be nested, that is, procedure A may contain procedure B, which in turn may contain C. In addition to data declared in B, B can also reference any data declared in A, as long as it doesn’t override the definition. Likewise C can reference data in both A and B. Therefore, PL/I ENTRY variables need to contain ''context'',<ref>{{cite book \|last1=Abrahams \|first1=Paul \|title=The PL/I Programming Language \|date=March 1978 \|publisher=Courant Mathematics and Computing Laboratory, New York University \|pages=22–24 \|url=http://www.iron-spring.com/abrahams.pdf \|access-date=April 4, 2025}}</ref> to provide procedure C with the addresses of the ~~current~~ values of data in B and A.		[[PL/I]] procedures can be nested, that is, procedure A may contain procedure B, which in turn may contain C. In addition to data declared in B, B can also reference any data declared in A, as long as it doesn’t override the definition. Likewise C can reference data in both A and B. Therefore, PL/I ENTRY variables need to contain ''context'',<ref>{{cite book \|last1=Abrahams \|first1=Paul \|title=The PL/I Programming Language \|date=March 1978 \|publisher=Courant Mathematics and Computing Laboratory, New York University \|pages=22–24 \|url=http://www.iron-spring.com/abrahams.pdf \|access-date=April 4, 2025}}</ref> to provide procedure C with the addresses of the values of data in B and A at the time C was called.

	==See also==		==See also==

Peter Flass: /* PL/I */ Add promised PL/I reference

2025-04-05T03:04:34Z

PL/I: Add promised PL/I reference

← Previous revision		Revision as of 03:04, 5 April 2025
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	==PL/I==		==PL/I==
	[[PL/I]] procedures can be nested, that is, procedure A may contain procedure B, which in turn may contain C. In addition to data declared in B, B can also reference any data declared in A, as long as it doesn’t override the definition. Likewise C can reference data in both A and B. Therefore, PL/I ENTRY variables need to contain ''context'', to provide procedure C with the addresses of the current values of data in B and A.		[[PL/I]] procedures can be nested, that is, procedure A may contain procedure B, which in turn may contain C. In addition to data declared in B, B can also reference any data declared in A, as long as it doesn’t override the definition. Likewise C can reference data in both A and B. Therefore, PL/I ENTRY variables need to contain ''context'',<ref>{{cite book \|last1=Abrahams \|first1=Paul \|title=The PL/I Programming Language \|date=March 1978 \|publisher=Courant Mathematics and Computing Laboratory, New York University \|pages=22–24 \|url=http://www.iron-spring.com/abrahams.pdf \|access-date=April 4, 2025}}</ref> to provide procedure C with the addresses of the current values of data in B and A.

	==See also==		==See also==

Peter Flass: /* See also */ PL/I - will add reference “soon”

2025-04-04T13:15:33Z

See also: PL/I - will add reference “soon”

← Previous revision		Revision as of 13:15, 4 April 2025
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	int RefP(C &p, FnC m, char c);		int RefP(C &p, FnC m, char c);
	</syntaxhighlight>		</syntaxhighlight>

			==PL/I==
			[[PL/I]] procedures can be nested, that is, procedure A may contain procedure B, which in turn may contain C. In addition to data declared in B, B can also reference any data declared in A, as long as it doesn’t override the definition. Likewise C can reference data in both A and B. Therefore, PL/I ENTRY variables need to contain ''context'', to provide procedure C with the addresses of the current values of data in B and A.

	==See also==		==See also==

AnomieBOT: Dating maintenance tags: {{What}}

2024-07-16T13:18:14Z

Dating maintenance tags: {{What}}

← Previous revision		Revision as of 13:18, 16 July 2024
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	Function pointers allow different code to be executed at runtime. They can also be passed to a function to enable [[callback (computer programming)\|callbacks]].		Function pointers allow different code to be executed at runtime. They can also be passed to a function to enable [[callback (computer programming)\|callbacks]].

	Function pointers are supported by [[third-generation programming language\|third-generation]] [[programming language]]s (such as [[PL/I]], [[COBOL]], [[Fortran]],<ref>{{cite web\|url=http://www.esm.psu.edu/~ajm138/fortranexamples.html#ex1\|title=Fortran Examples\|author=Andrew J. Miller\|access-date=2013-09-14}}</ref> [[dBASE]] dBL{{what}}, and [[C (programming language)\|C]]) and [[object-oriented programming]] languages (such as [[C++]], [[C Sharp (programming language)\|C#]], and [[D (programming language)\|D]]).<ref>{{cite web\|url=http://www.newty.de/fpt/intro.html#what\|title=The Function Pointer Tutorials\|publisher=logo\|access-date=2011-04-13\|quote=Function Pointers are pointers, i.e. variables, which point to the address of a function\|archivedate=2011-05-16\|archiveurl=https://web.archive.org/web/20110516153643/http://www.newty.de/fpt/intro.html#what\|url-status=deviated}}</ref>		Function pointers are supported by [[third-generation programming language\|third-generation]] [[programming language]]s (such as [[PL/I]], [[COBOL]], [[Fortran]],<ref>{{cite web\|url=http://www.esm.psu.edu/~ajm138/fortranexamples.html#ex1\|title=Fortran Examples\|author=Andrew J. Miller\|access-date=2013-09-14}}</ref> [[dBASE]] dBL{{what\|date=July 2024}}, and [[C (programming language)\|C]]) and [[object-oriented programming]] languages (such as [[C++]], [[C Sharp (programming language)\|C#]], and [[D (programming language)\|D]]).<ref>{{cite web\|url=http://www.newty.de/fpt/intro.html#what\|title=The Function Pointer Tutorials\|publisher=logo\|access-date=2011-04-13\|quote=Function Pointers are pointers, i.e. variables, which point to the address of a function\|archivedate=2011-05-16\|archiveurl=https://web.archive.org/web/20110516153643/http://www.newty.de/fpt/intro.html#what\|url-status=deviated}}</ref>

	==Simple function pointers==		==Simple function pointers==

Apokrif: No obvious wkf target for dBL.

2024-07-16T12:57:40Z

No obvious wkf target for dBL.

← Previous revision		Revision as of 12:57, 16 July 2024
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	Function pointers allow different code to be executed at runtime. They can also be passed to a function to enable [[callback (computer programming)\|callbacks]].		Function pointers allow different code to be executed at runtime. They can also be passed to a function to enable [[callback (computer programming)\|callbacks]].

	Function pointers are supported by [[third-generation programming language\|third-generation]] [[programming language]]s (such as [[PL/I]], [[COBOL]], [[Fortran]],<ref>{{cite web\|url=http://www.esm.psu.edu/~ajm138/fortranexamples.html#ex1\|title=Fortran Examples\|author=Andrew J. Miller\|access-date=2013-09-14}}</ref> dBASE dBL, and [[C (programming language)\|C]]) and [[object-oriented programming]] languages (such as [[C++]], [[C Sharp (programming language)\|C#]], and [[D (programming language)\|D]]).<ref>{{cite web\|url=http://www.newty.de/fpt/intro.html#what\|title=The Function Pointer Tutorials\|publisher=logo\|access-date=2011-04-13\|quote=Function Pointers are pointers, i.e. variables, which point to the address of a function\|archivedate=2011-05-16\|archiveurl=https://web.archive.org/web/20110516153643/http://www.newty.de/fpt/intro.html#what\|url-status=deviated}}</ref>		Function pointers are supported by [[third-generation programming language\|third-generation]] [[programming language]]s (such as [[PL/I]], [[COBOL]], [[Fortran]],<ref>{{cite web\|url=http://www.esm.psu.edu/~ajm138/fortranexamples.html#ex1\|title=Fortran Examples\|author=Andrew J. Miller\|access-date=2013-09-14}}</ref> [[dBASE]] dBL{{what}}, and [[C (programming language)\|C]]) and [[object-oriented programming]] languages (such as [[C++]], [[C Sharp (programming language)\|C#]], and [[D (programming language)\|D]]).<ref>{{cite web\|url=http://www.newty.de/fpt/intro.html#what\|title=The Function Pointer Tutorials\|publisher=logo\|access-date=2011-04-13\|quote=Function Pointers are pointers, i.e. variables, which point to the address of a function\|archivedate=2011-05-16\|archiveurl=https://web.archive.org/web/20110516153643/http://www.newty.de/fpt/intro.html#what\|url-status=deviated}}</ref>

	==Simple function pointers==		==Simple function pointers==

Panamitsu: removed Category:Data types; added Category:Pointers (computer programming) using HotCat

2024-06-03T23:22:44Z

removed Category:Data types; added Category:Pointers (computer programming) using HotCat

← Previous revision		Revision as of 23:22, 3 June 2024
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	* [http://www.dbase.com/help/2_80/Language_Definition/IDH_LDEF_FUNCPOINTERS.htm Function Pointers in dBASE dBL], Function Pointer in dBASE dBL		* [http://www.dbase.com/help/2_80/Language_Definition/IDH_LDEF_FUNCPOINTERS.htm Function Pointers in dBASE dBL], Function Pointer in dBASE dBL

	[[Category:~~Data~~ ~~types~~]]		[[Category:Pointers (computer programming)]]
	[[Category:Subroutines]]		[[Category:Subroutines]]
	[[Category:Articles with example C code]]		[[Category:Articles with example C code]]

InternetArchiveBot: Rescuing 3 sources and tagging 0 as dead.) #IABot (v2.0.9.5

2024-05-14T17:25:44Z

Rescuing 3 sources and tagging 0 as dead.) #IABot (v2.0.9.5

← Previous revision		Revision as of 17:25, 14 May 2024
Line 5:		Line 5:
	Function pointers allow different code to be executed at runtime. They can also be passed to a function to enable [[callback (computer programming)\|callbacks]].		Function pointers allow different code to be executed at runtime. They can also be passed to a function to enable [[callback (computer programming)\|callbacks]].

	Function pointers are supported by [[third-generation programming language\|third-generation]] [[programming language]]s (such as [[PL/I]], [[COBOL]], [[Fortran]],<ref>{{cite web\|url=http://www.esm.psu.edu/~ajm138/fortranexamples.html#ex1\|title=Fortran Examples\|author=Andrew J. Miller\|access-date=2013-09-14}}</ref> dBASE dBL, and [[C (programming language)\|C]]) and [[object-oriented programming]] languages (such as [[C++]], [[C Sharp (programming language)\|C#]], and [[D (programming language)\|D]]).<ref>{{cite web\|url=http://www.newty.de/fpt/intro.html#what\|title=The Function Pointer Tutorials\|publisher=logo\|access-date=2011-04-13\|quote=Function Pointers are pointers, i.e. variables, which point to the address of a function}}</ref>		Function pointers are supported by [[third-generation programming language\|third-generation]] [[programming language]]s (such as [[PL/I]], [[COBOL]], [[Fortran]],<ref>{{cite web\|url=http://www.esm.psu.edu/~ajm138/fortranexamples.html#ex1\|title=Fortran Examples\|author=Andrew J. Miller\|access-date=2013-09-14}}</ref> dBASE dBL, and [[C (programming language)\|C]]) and [[object-oriented programming]] languages (such as [[C++]], [[C Sharp (programming language)\|C#]], and [[D (programming language)\|D]]).<ref>{{cite web\|url=http://www.newty.de/fpt/intro.html#what\|title=The Function Pointer Tutorials\|publisher=logo\|access-date=2011-04-13\|quote=Function Pointers are pointers, i.e. variables, which point to the address of a function\|archivedate=2011-05-16\|archiveurl=https://web.archive.org/web/20110516153643/http://www.newty.de/fpt/intro.html#what\|url-status=deviated}}</ref>

	==Simple function pointers==		==Simple function pointers==
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	\| title = The Function Pointer Tutorials		\| title = The Function Pointer Tutorials
	\| quote = Important note: A function pointer always points to a function with a specific signature! Thus all functions, you want to use with the same function pointer, must have the same parameters and return-type!		\| quote = Important note: A function pointer always points to a function with a specific signature! Thus all functions, you want to use with the same function pointer, must have the same parameters and return-type!
	\| url = http://www.newty.de/fpt/intro.html#top~~}}</ref>~~		\| url = http://www.newty.de/fpt/intro.html#top
			\| archivedate = 2011-05-16
			\| archiveurl = https://web.archive.org/web/20110516153643/http://www.newty.de/fpt/intro.html#top
			\| url-status = deviated
			}}</ref>

	=== Example in C ===		=== Example in C ===
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	==External links==		==External links==
	* [https://web.archive.org/web/20041013202445/http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.12 FAQ on Function Pointers], things to avoid with function pointers, some information on using [[function object]]s		* [https://web.archive.org/web/20041013202445/http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.12 FAQ on Function Pointers], things to avoid with function pointers, some information on using [[function object]]s
	* [http://www.newty.de/fpt/ Function Pointer Tutorials], a guide to C/C++ function pointers, [[callback (computer programming)\|callbacks]], and [[function object]]s (functors)		* [http://www.newty.de/fpt/ Function Pointer Tutorials] {{Webarchive\|url=https://web.archive.org/web/20180630152057/http://www.newty.de/fpt/ \|date=2018-06-30 }}, a guide to C/C++ function pointers, [[callback (computer programming)\|callbacks]], and [[function object]]s (functors)
	* [http://www.codeproject.com/KB/cpp/FastDelegate.aspx Member Function Pointers and the Fastest Possible C++ Delegates], CodeProject article by Don Clugston		* [http://www.codeproject.com/KB/cpp/FastDelegate.aspx Member Function Pointers and the Fastest Possible C++ Delegates], CodeProject article by Don Clugston
	* [http://www.cplusplus.com/doc/tutorial/pointers.html Pointer Tutorials] {{Webarchive\|url=https://web.archive.org/web/20090405234937/http://www.cplusplus.com/doc/tutorial/pointers.html \|date=2009-04-05 }}, C++ documentation and tutorials		* [http://www.cplusplus.com/doc/tutorial/pointers.html Pointer Tutorials] {{Webarchive\|url=https://web.archive.org/web/20090405234937/http://www.cplusplus.com/doc/tutorial/pointers.html \|date=2009-04-05 }}, C++ documentation and tutorials

2A02:A317:2341:D880:481A:5E06:A1F7:EFE0: deleted unnecessary std::

2024-01-16T18:34:00Z

deleted unnecessary std::

← Previous revision		Revision as of 18:34, 16 January 2024
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	int main() {		int main() {
	double x = 1;		double x = 1;
	cout << "d/dx(x ^ 2) [@ x = " << x << "] = " << derivative(f, x, 1e-5) << ~~std::~~endl;		cout << "d/dx(x ^ 2) [@ x = " << x << "] = " << derivative(f, x, 1e-5) << endl;
	return 0;		return 0;
	}		}

Physidev: /* Pointers to member functions in C++ */

2023-12-30T23:03:36Z

Pointers to member functions in C++

← Previous revision		Revision as of 23:03, 30 December 2023
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	=== Pointers to member functions in C++ ===		=== Pointers to member functions in C++ ===
	{{See also\|#Alternate C and C++ ~~Syntax~~}}		{{See also\|#Alternate C and C++ syntax}}
	This is how C++ uses function pointers when dealing with member functions of classes or structs. These are invoked using an object pointer or a this call. They are type safe in that you can only call members of that class (or derivatives) using a pointer of that type. This example also demonstrates the use of a typedef for the pointer to member function added for simplicity. Function pointers to static member functions are done in the traditional 'C' style because there is no object pointer for this call required.		This is how C++ uses function pointers when dealing with member functions of classes or structs. These are invoked using an object pointer or a this call. They are type safe in that you can only call members of that class (or derivatives) using a pointer of that type. This example also demonstrates the use of a typedef for the pointer to member function added for simplicity. Function pointers to static member functions are done in the traditional 'C' style because there is no object pointer for this call required.

14.139.223.172: /* In C++ */

2023-08-16T18:42:41Z

In C++

← Previous revision		Revision as of 18:42, 16 August 2023
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	#include <iostream>		#include <iostream>
	#include <functional>		#include <functional>
			using namespace std;

	static double derivative(const ~~std::~~function<double(double)> &f, double x0, double eps) {		static double derivative(const function<double(double)> &f, double x0, double eps) {
	double eps2 = eps / 2;		double eps2 = eps / 2;
	double lo = x0 - eps2;		double lo = x0 - eps2;
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	int main() {		int main() {
	double x = 1;		double x = 1;
	~~std::~~cout << "d/dx(x ^ 2) [@ x = " << x << "] = " << derivative(f, x, 1e-5) << std::endl;		cout << "d/dx(x ^ 2) [@ x = " << x << "] = " << derivative(f, x, 1e-5) << std::endl;
	return 0;		return 0;
	}		}