Operator * (Value Of)

Dereferences a pointer

Syntax
   Declare Operator * ( ByRef rhs As T Pointer ) ByRef As T

Usage
      result = * rhs
   or
      * rhs = value

Parameters
   rhs
      The address to dereference.
   T
      Any standard, user-defined or procedure type.

Return Value
   Returns a reference to the value stored at the address rhs.

Description
   Operator * (Value of) returns a reference to the value stored at an 
   address, and is often called the dereference operator. The operand is 
   not modified in any way.
   Any type of Pointer can be dereferenced except for an Any Pointer.

   As a reference, the result of this operator can be used on the left-hand 
   side of assignments.

   This operator must not be used in case of null pointer because reference 
   is undefined (inducing runtime error).
   Otherwise, the user must ensure that the pointer value induces access to 
   a valid memory. Otherwise, results are undefined.

   This operator can be overloaded for user-defined types.

Example
   'This program demonstrates the use of * to utilize the value a pointer points to.
   Dim a As Integer
   Dim pa As Integer Ptr

   pa=@a 'Here, we use the @ operator to point our integer ptr at 'a'.
   ' 'a' is, in this case, a standard integer variable.

   a=9     'Here we give 'a' a value of 9.

   Print "The value of 'a' is";*pa 'Here, we display the value of 'a' using a pointer. 

   *pa = 1 'Here we use our pointer to change the value of 'a'
   Print "The new value of 'a' is";a 'Here we display the new value of 'a'.

Output:

   The value of 'a' is 9
   The New value of 'a' is 1

Dialect Differences
   * In the -lang qb dialect, this operator cannot be overloaded.

Differences from QB
   * New to FreeBASIC

See also
   * Operator @ (Address Of)
   * Operator [] (Pointer Index)
   * Pointers

