function pointer

For example, in C it is possible to define a function pointer.

The function pointer is then simply the address of the trampoline.

The block may be later invoked in the same manner as a function pointer.

Dynamic dispatch can be done by looking up this value in a function pointer branch table.

It is not possible to implement computed jumps or function pointers.

Without a function that takes function pointer the following code would have to be used.

C allows functions to be indirectly invoked through a function pointer.

Function pointers are invoked by name just like normal function calls.

Instead of referring to data values, a function pointer points to executable code within memory.

Following that, it will hold a set of function pointers - one for each virtual method of the class.

This is done by giving along with the system call a structure containing, among others, a function pointer to the signal handling routine.

A C program using function pointers may appear as:

The function pointer will store the address location of the function to be invoked.

Some find C's declaration syntax unintuitive, particularly for function pointers.

Thus, it is made hard for any unauthorized user of the function pointer to be able to actually use it.

However, this is not strictly the case here, since the function pointer is copied to be used outside the union.

The following program shows use of a function pointer for selecting between addition and subtraction:

A callback in procedural languages, such as C, may be performed by using function pointers.

C, C++ and Pascal allow function pointers as arguments to other functions.

Function pointers especially are a problem here, as they can be overflowed into and will execute shellcode when called.

Function pointers allow referencing functions with a particular signature.

Many "pure" object-oriented languages do not support function pointers.

This substitution is typically done through the reassignment of known function pointers or object replacement.

Limit pointer use to a single dereference, and do not use function pointers.

By overwriting a function pointer, or exception handler, which is subsequently executed.