void pointer in C / C++
A void pointer is a pointer that has no associated data type with it. A void pointer can hold address of any type and can be typecasted to any type.
Advantages of void pointers:
1) malloc() and calloc() return void * type and this allows these functions to be used to allocate memory of any data type (just because of void *)
Note that the above program compiles in C, but doesn’t compile in C++. In C++, we must explicitly typecast return value of malloc to (int *).
2) void pointers in C are used to implement generic functions in C. For example compare function which is used in qsort().
Some Interesting Facts:
1) void pointers cannot be dereferenced. For example the following program doesn’t compile.
Compiler Error: 'void*' is not a pointer-to-object type
The following program compiles and runs fine.
2) The C standard doesn’t allow pointer arithmetic with void pointers. However, in GNU C it is allowed by considering the size of void is 1. For example the following program compiles and runs fine in gcc.
Note that the above program may not work in other compilers.
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