cvariablesstaticdeclarationstorage-class-specifier

Declaration specifiers and declarators


With reference to the question Where in a declaration may a storage class specifier be placed? I started analyzing the concept of declaration-specifiers and declarators. Following is the accumulation of my understanding.

Declarations

Rules that I assume

Questions

Q1: In the declaration of a constant pointer, I see a mix of declarator and type-qualifier as below

const int *const ptr; //Need justification for the mix of declarator and type-specifier

Q2: There can be a pointer to static int. Is there a possibility of providing the pointer a static storage class? Means the pointer being static.


Solution

  • I'm not sure I full understand you first question. In terms of C++03 grammar const is a cv-qualifier. cv-qualifier can be present in decl-specifier-seq (as a specific kind of type-specifier), which is a "common" part of the declaration, as well as in init-declarator-list, which is a comma-separated sequence of individual declarators.

    The grammar is specifically formulated that a const specifier belonging to an individual pointer declarator must follow the *. A const specifier that precedes the first * is not considered a part of the individual declarator. This means that in this example

    int const *a, *b;
    

    const belongs to the left-hand side: decl-specifier-seq, the "common" part of the declaration. I.e. both a and b are declared as int const *. Meanwhile this

    int *a, const *b;
    

    is simply ill-formed and won't compile.

    Your second question doesn't look clear to me either. It seems that you got it backwards. You claim that "there can be a pointer to static int"? No, there's no way to declare such thing as "pointer to static int". You can declare a static pointer to int though

    static int *p;
    

    In this case the pointer itself is static, as you wanted it to be.