It defines a pointer-to-function type. The functions return void, and the argument list is unspecified because the question is (currently, but possibly erroneously) tagged C; if it were tagged C++, then the function would take no arguments at all. To make it a function that takes no arguments (in C), you’d use: typedef void (*MCB)(void); … Read more
While it might be tempting to conclude that all pointers are the same size because “pointers are just addresses, and addresses are just numbers of the same size”, it is not guaranteed by the standard and thus cannot be relied upon. The C++ standard explicitly guarantees that: void* has the same size as char* ([basic.compound]/5) … Read more
You can cast it to an intptr_t type. It’s an int type guaranteed to be big enough to contain a pointer. Use #include <cstdint> to define it.
Deleting via a void pointer is undefined by the C++ Standard – see section 5.3.5/3: In the first alternative (delete object), if the static type of the operand is different from its dynamic type, the static type shall be a base class of the operand’s dynamic type and the static type shall have a virtual … Read more
A void* does not mean anything. It is a pointer, but the type that it points to is not known. It’s not that it can return “anything”. A function that returns a void* generally is doing one of the following: It is dealing in unformatted memory. This is what operator new and malloc return: a … Read more
Is it possible to dereference the void pointer without type-casting in C programming language… No, void indicates the absence of type, it is not something you can dereference or assign to. is there is any way of generalizing a function which can receive pointer and store it in void pointer and by using that void … Read more
void * means “a reference to some random chunk o’ memory with untyped/unknown contents” id means “a reference to some random Objective-C object of unknown class” There are additional semantic differences: Under GC Only or GC Supported modes, the compiler will emit write barriers for references of type id, but not for type void *. … Read more
There is a rule called the “Clockwise/Spiral Rule” to help find the meaning of a complex declaration. From c-faq: There are three simple steps to follow: Starting with the unknown element, move in a spiral/clockwise direction; when ecountering the following elements replace them with the corresponding english statements: [X] or [] => Array X size … Read more
Final conclusion: arithmetic on a void* is illegal in both C and C++. GCC allows it as an extension, see Arithmetic on void– and Function-Pointers (note that this section is part of the “C Extensions” chapter of the manual). Clang and ICC likely allow void* arithmetic for the purposes of compatibility with GCC. Other compilers … Read more