CWG Issue 83

This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-11-11

83. Overloading and deprecated conversion of string literal

Section: 12.2.4.3 [over.ics.rank] Status: TC1 Submitter: Steve Adamczyk Date: 24 Jan 1999

In 12.2.4.3 [over.ics.rank] , we have

S1 and S2 differ only in their qualification conversion and yield similar types T1 and T2 (7.3.6 [conv.qual] ), respectively, and the cv-qualification signature of type T1 is a proper subset of the cv-qualification signature of type T2, [Example:
```
    int f(const int *);
    int f(int *);
    int i;
    int j = f(&i); // Calls f(int *)
```
—end example] or, if not that,

This does not work right with respect to the deprecated conversion from string literal to "char *". Consider

    void f(char *);
    void f(const char *);

    f("abc");

The two conversion sequences differ only in their qualification conversions, and the destination types are similar. The cv-qualification signature of "char *", is a proper subset of the cv-qualification signature of "const char *", so f(char *) is chosen, which is wrong. The rule should be like the one for conversion to bool — the deprecated conversion should be worse than another exact match that is not the deprecated conversion.

Proposed resolution (10/00):

Change 12.2.4.3 [over.ics.rank] bullet 3.1 sub-bullet 3 from

S1 and S2 differ only in their qualification conversion and yield similar types T1 and T2 (7.3.6 [conv.qual] ), respectively, and the cv-qualification signature of type T1 is a proper subset of the cv-qualification signature of type T2.

S1 and S2 differ only in their qualification conversion and yield similar types T1 and T2 (7.3.6 [conv.qual] ), respectively, and the cv-qualification signature of type T1 is a proper subset of the cv-qualification signature of type T2, and S1 is not the deprecated string literal array-to-pointer conversion (7.3.3 [conv.array] ).