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Function overloading is usually associated with statically-typed programming languages that enforce type checking in function calls. An overloaded function is a set of different functions that are callable with the same name. For any particular call, the compiler determines which overloaded function to use and resolves this at compile time ...
Multiple dispatch or multimethods is a feature of some programming languages in which a function or method can be dynamically dispatched based on the run-time (dynamic) type or, in the more general case, some other attribute of more than one of its arguments. [1]
Virtual functions allow a program to call methods that don't necessarily even exist at the moment the code is compiled. [citation needed] In C++, virtual methods are declared by prepending the virtual keyword to the function's declaration in the base class. This modifier is inherited by all implementations of that method in derived classes ...
The overridden base method must be virtual, abstract, or override. In addition to the modifiers that are used for method overriding, C# allows the hiding of an inherited property or method. This is done using the same signature of a property or method but adding the modifier new in front of it. [6] In the above example, hiding causes the following:
The C++ standards do not mandate exactly how dynamic dispatch must be implemented, but compilers generally use minor variations on the same basic model. Typically, the compiler creates a separate virtual method table for each class.
Thus, there is no name collision, and no virtual table lookup. By contrast, dynamic dispatch is based on the type of the calling object, meaning it uses virtual functions (overriding) instead of function overloading, and does result in a vtable lookup. Consider the following example, written in C++, of collisions in a game:
Using it on a function definition may yield unexpected results, depending on the compiler and optimization level. [11] In Solaris, the weak symbols are also used within kernel. The generic part of kernel (called genunix) specifies weak functions that are overridden in platform specific part of the kernel (called unix) such as Virtual memory ...
32-bit compilers emit, respectively: _f _g@4 @h@4 In the stdcall and fastcall mangling schemes, the function is encoded as _name@X and @name@X respectively, where X is the number of bytes, in decimal, of the argument(s) in the parameter list (including those passed in registers, for fastcall).