Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Closure (computer science) - Wikipedia, the free encyclopedia Closures are commonly used in functional programming to defer calculation, to hide state, and as arguments to higher-order functions. Closures are typically implemented with a special data structure that contains a pointer to the function code, plus a representation of the function's lexical environment (i.e., the set of available variables and their values) at the time when the function was created. Closures typically appear in languages in which functions are first-class values—in other words, such languages allow functions to be passed as arguments, returned from function calls, bound to variable names, etc., just like simpler types such as strings and integers. en.wikipedia.org /wiki/Closure_(computer_science)   (1380 words)

Encyclopedia :: encyclopedia : Trigonometric function   (Site not responding. Last check: 2007-10-23) In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. The earliest systematic study of trigonometric functions and tabulation of their values was performed by Hipparchus of Nicaea (180-125 BC), who tabulated the lengths of circle arcs (angle A times radius r) with the lengths of the subtending chords (2r sin(A/2)). The computation of trigonometric functions is a complicated subject, which can today be avoided by most people because of the widespread availability of computers and scientific calculators that provide built-in trigonometric functions for any angle. www.hallencyclopedia.com /Trigonometric_function   (3250 words)

Function pointer adapters :: Generic algorithms - MYCPLUS In this case, we want the function object to wrap one of the member functions of the class itself, and so the function object’s “argument” becomes the pointer to the object that the member function is called for. The mem_fun() functions are for producing function objects that are called using a pointer to the object that the member function is called for, while mem_fun_ref() is used for calling the member function directly for an object. Notice that the transform() and for_each() template functions are incomplete; transform() requires that the function it calls return a value, and there is no for_each() that passes two arguments to the function it calls. www.mycplus.com /tutorial.asp?TID=143   (1108 words)

Pointers to C++ Member Functions Member function pointers are important because they provide an efficient way to cache the outcome of a decision over which member function to call. Using the wrong setting for your project may result in an apparently gross code generation bug, because a member function pointer returned by a function that supplies them may have a different size than the recipient function expects, causing bogus data to be overwritten on the stack. One of the best uses for member function pointers is caching the outcome of a decision over which ofseveral member functions should be called in a particular circumstance. linuxquality.sunsite.dk /articles/memberpointers   (2133 words)

The Function Pointer Tutorials Static member functions do not need an object to be invoked on and thus have the same signature as a C function with the same calling convention, calling arguments and return type. Pointers to non-static members are different to ordinary C function pointers since they need the this-pointer of a class object to be passed. Therefore a pointer to an object of class TClassA and a pointer to the static wrapper function TClassA::Wrapper_To_Call_Display are passed to DoItA. oopweb.com /CPP/Documents/FunctionPointers/Volume/CCPP/callback/callback.html   (1531 words)

Calling C Pointer-type Function from Fortran In Intel® Fortran, the result of a C pointer-type function is passed by reference as an additional, hidden argument. The function’s result (int *) is returned as a pointer to a pointer (int **), and the C function must be of type void (not int*). In addition to pointer-type functions, the same mechanism should be used for Fortran functions of user-defined type, since they are also returned by reference as a hidden argument. www.wpi.edu /Academics/CCC/Unix/Docs/ifc/f_ug/mix_callp.htm   (152 words)

A Proposal to add a Polymorphic Function Object Wrapper to the Standard Library Function pointers in C and C++ are used in both user and library code to customize the behavior of components by substituting a user-supplied function for part of a computation. Several function object wrappers (often referred to as "callbacks") have appeared with similar interfaces [1, 2, 10, 11], suggesting that this class template is appropriate for standardization. Polymorphic function object wrappers may also be used in lieu of arbitrary function objects whose type is a template parameter, allowing a trivial switch from function templates to functions (with a corresponding size/speed tradeoff). std.dkuug.dk /jtc1/sc22/wg21/docs/papers/2002/n1402.html   (2122 words)

Declaring Function Pointers and Implementing Callbacks   (Site not responding. Last check: 2007-10-23) A callback function is one that is not invoked explicitly by the programmer; rather the responsibility for its invocation is delegated to another function that receives the callback function's address. The asterisk in the leftmost parentheses is the nucleus of a function pointer declaration. It's important to note that the calling convention is an integral part of a function's type; you can't assign an address of a function to a pointer with an incompatible calling convention. www.inquiry.com /techtips/cpp_pro/10min/10min0300.asp   (897 words)

The Function Pointer Tutorials Regarding their syntax, there are two different types of function pointers: On the one hand there are pointers to ordinary C functions or static C++ member functions, on the other hand there are pointers to non-static C++ member functions. Since a function pointer is nothing else than a variable, it must be defined as usual. In C you have two alternatives of how to call a function using a function pointer: You can just use the name of the function pointer instead of the name of the function or you can explicitly dereference it. oopweb.com /CPP/Documents/FunctionPointers/Volume/CCPP/FPT/em_fpt.html   (2083 words)

Defining a Function Object   (Site not responding. Last check: 2007-10-23) Although pointers to functions are widely used for implementing function callbacks, C++ offers a significantly superior alternative to them, namely function objects. Function objects (also called "functors") are ordinary class objects that overload the () operator. There are several advantages in using a function object instead of a pointer to function. www.inquiry.com /techtips/cpp_pro/10min/10min0100.asp   (807 words)

INFO: Creating a Function Pointer to a C++ Member Function The different ways to interpret the empty parentheses in function declarations is a major difference between the C and C++ languages. A pointer to a static member function is declared in the same manner as a pointer to a C function. Note that when the arguments in the function pointer declaration do not match the arguments of the function assigned to the pointer, the compiler generates errors C2440 and C2564. support.microsoft.com /support/kb/articles/q94/5/79.ASP   (699 words)

Dr. Dobb's | From Mechanism to Method: Function Follows Form | April 15, 2003 The member pointer type need not be a member function pointer; a member data pointer that points to a nullary function object will also work. The remember template function is a helper that simplifies composition of remember_function objects, automatically deducing the parameter types in the manner of make_pair for pair, bind2nd for binder2nd, or ptr_fun for pointer_to_unary_function and pointer_to_binary_function. Function objects at first appear to offer a route out: A nullary function pointer or object could be passed in, including a remember_function binding of member to target, and later called back. www.ddj.com /dept/cpp/184403753   (3181 words)

Extracting the function pointer from a bound pointer to member function pointer, and if the function pointed to is virtual, where to find the vtable, and where in the vtable to look for the member function. If that is not an option, you can extract the pointer to the function that would be called for a given object/PMF pair and call it directly inside the inner loop, to save a bit of time. Note that you will still be paying the penalty for the call through a function pointer; on most modern architectures, such a call defeats the branch prediction features of the CPU. www.redhat.com /docs/manuals/enterprise/RHEL-3-Manual/gcc/bound-member-functions.html   (229 words)

some function pointer troubles - GameDev.Net Discussion Forums   (Site not responding. Last check: 2007-10-23) Member function pointers are not automatically linked to any specific class instance, so just because you store them in one button doesn't mean you have to invoke them on the same instance. The difference between regular function pointers and member function pointers is, as the name implies, that you can call member functions through member function pointers. I think you don't yet quite understand pointer to member functions they are a completely different beast from pointer to functions. www.gamedev.net /community/forums/topic.asp?topic_id=307821   (899 words)

Page 2 - Function Pointers, part 2 The main difference lies in the fact that you have to specify the class scope of the function pointer, so that the compiler understands that the function pointer is aimed at the member of a class. The function pointer above may come as a small surprise, because you would expect the code of an inlined member function to be pasted into where we normally would find the function call. However when you declare a member function pointer to an inlined function, the compiler creates a body for that function so that it can be executed when you call that member function pointer. www.devarticles.com /c/a/Cplusplus/Funtion-Pointers-part-2/1   (1110 words)

Dr. Dobb's | Generalizing Observer | July 29, 2003 The function facility, recently adopted by the C++ standards committee, provides a generalized way of working with arbitrary functions when all you know (or need to know) is their approximate signature. In brief, the function facility provides a generalized way of working with arbitrary functions when all you know (or need to know) is their signature. I hope you'll agree that this is a compelling advantage of using function over one of the more hardwired alternatives, and a compelling structural generalization over the original OO structure for Observer described in [4], which originally worked only with a hardwired inheritance hierarchy and a single preset virtual function name and exact signature match. www.ddj.com /dept/cpp/184403873   (3601 words)

Favor the Function Object to the Function Pointer in STL Algorithms Pass either a function pointer or a function object as its third argument, which returns true and false according to your logic. The invocation of a function through a function pointer is an indirect invocation which prevents the compiler from inlining said function—even if it is a good candidate for inlining. When you use the function object, if the operator() is defined inline and the compiler deems it a suitable candidate for inlining, then the compiler will inline it, thus enhancing performance. www.devx.com /tips/Tip/22530   (379 words)

Function Objects An ordinary function is a function object, and so is a function pointer; more generally, so is an object of a class that defines In this example, the function object is an object of a user-defined class. In this example, the function object is of a user-defined class that has local state. www.sgi.com /tech/stl/functors.html   (552 words)

'dynamic' function pointer argument list   (Site not responding. Last check: 2007-10-23) For each function I have a list of the supplied argumentstype (which of course could be different for each function). The way I solved that problem in a similar project was to pass a pointer to a (linked) list of function arguments to the functions, where (in principle) each element of the list consists of an int with type information and an union for the argument value, with a member for each possible type. Functions with variadic arguments are functions like printf() that are typically declared as int printf(const char *format,... www.codecomments.com /message236946.html   (956 words)

Embedded System Encyclopedia Articles @ HotAndCold.com (Hot and Cold)   (Site not responding. Last check: 2007-10-23) For example the first microprocessor was the Intel 4004, which found its way into calculators and other small systems, but required external memory and support chips. For example, a digital set-top box for satellite television has to process large amounts of data every second, but most of the processing is done by custom integrated circuits. Because of these complexities, it is common for organizations to buy a real-time operating system, allowing the application programmers to concentrate on device functionality rather than operating system services. www.hotandcold.com /encyclopedia/Embedded_system   (2909 words)

Example of function returning pointer to function.   (Site not responding. Last check: 2007-10-23) /* This is an example demonstrating a function that returns a pointer to a function. /* funcptr is a pointer to a function that takes a single argument of type char and returns nothing. Since f points to function foo(), which takes a single argument of type char, we want to pass it a single char argument. community.borland.com /article/0,1410,15973,00.html   (317 words)

24.1 Declaring, Assigning, and Using Function Pointers   (Site not responding. Last check: 2007-10-23) (The fact that a function pointer is generated automatically when a function appears in an expression but is not being called is very similar to, and in fact related to, the fact that a pointer to the first element of an array is generated automatically when an array appears in an expression.) Finally, once we have a function pointer variable which does point to a function, we can call the function that it points to. There's nothing you can do with a function pointer except assign it to another function pointer, compare it to another function pointer, or call the function that it points to. www.eskimo.com /~scs/cclass/int/sx10a.html   (684 words)

#66336: FORTE--How do I wrapper a C function pointer?? You would have to do this indirectly by having another C function that would invoke the function pointer. Here is an example of a C class that would do this: class useFunctionPointer returnFunctionPointer() : pointer; callFunctionPointer(p : pointer, a1 : int); end; In this case, the function returnFunctionPointer is a C routine that is going to return a function pointer to the TOOL code. The function callFunctionPointer uses the passed-in function pointer to call the function. sunsolve.sun.com /search/document.do?assetkey=1-9-66336-1   (263 words)

:function   (Site not responding. Last check: 2007-10-23) It is typically used in conjunction with the :pointer type to reference an existing foreign function. The following code lines present a definition of a pointer to a function type, and a corresponding C definition of the type. The function type is defined for a function which takes as its arguments an integer and a pointer to a void, and returns an integer value. www.lispworks.com /documentation/lw445/FLI/html/fli-140.htm   (77 words)

member function pointer problem when using as arguments - dBforums I'm using a member function to set a member variable which is a function pointer. > I'm using a member function to set a member variable which is a function pointer. You cannot use function pointers to non-static member functions, AFAIK. www.dbforums.com /t389519.html   (604 words)

Function pointer compile error - Dev Shed Function pointer compile error C programming forum discussing all C derivatives, including C#, C++, Object-C, and even plain old vanilla C. These languages are low level languages, and used on projects such as device drivers, compilers, and even whole computer operating systems. Alright after a bunch of research, i've found that the problem was that the parameter must include the class which the function that will be pointed to resides in. This is a huge problem because the whole purpose of this function was to get a pointer to another classes handle command function. forums.devshed.com /c-programming-42/function-pointer-compile-error-291817.html   (405 words)

Function pointer parameter From C,I called an assembly function passing in generic pointer and a function pointer. I can access the first parameter (generic pointer) by taking in the values from R2 and R1 but I have difficulty getting the second parameter. This assembly function is suppose to get the address of the function (therefore the function pointer is passed in) and store it in another location. www.keil.com /discuss/docs/thread4017.htm   (121 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.