6.7.5.1 Pointer declarators

Previous Table of Contents "New C Standard" commentary

1560 If, in the declaration “T D1”, D1 has the form

        * type-qualifier-list_opt D

and the type specified for ident in the declaration “T D” is “derived-declarator-type-list T”, then the type specified for ident is “derived-declarator-type-list type-qualifier-list pointer to T”.

1561 For each type qualifier in the list, ident is a so-qualified pointer.

1562 For two pointer types to be compatible, both shall be identically qualified and both shall be pointers to compatible types.

1563 EXAMPLE The following pair of declarations demonstrates the difference between a “variable pointer to a constant value” and a “constant pointer to a variable value”.


        const int *ptr_to_constant;
        int *const constant_ptr;

The contents of any object pointed to by ptr_to_constant shall not be modified through that pointer, but ptr_to_constant itself may be changed to point to another object. Similarly, the contents of the int pointed to by constant_ptr may be modified, but constant_ptr itself shall always point to the same location.

The declaration of the constant pointer constant_ptr may be clarified by including a definition for the type “pointer to int”.


        typedef int *int_ptr;
        const int_ptr constant_ptr;

declares constant_ptr as an object that has type “const-qualified pointer to int”.