22.5.3 Calling Function Pointers

To call the function specified by a function pointer, just write the function pointer value in a function call. For instance, here’s a call to the function binary_op points to:

binary_op (x, 5)

Since the data type of binary_op explicitly specifies type double for the arguments, the call converts x and 5 to double.

The call conceptually dereferences the pointer binary_op to “get” the function it points to, and calls that function. If you wish, you can explicitly represent the derefence by writing the * operator:

(*binary_op) (x, 5)

The ‘*’ reminds people reading the code that binary_op is a function pointer rather than the name of a specific function.