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Frederick Gotham
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 Posted: Tue Oct 03, 2006 9:08 pm Post subject: String literal pointer decay funkiness... |
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The type of a string literal is:
char const[sizeof "whatever is written"]
However, it decays to a pointer to non-const, rather than a pointer to const.
Here's some funky code:
void Func(char*) {}
void Func(char const*) {}
int main()
{
Func("Hello");
}
I would have thought that the "char*" version would be invoked, but it seems
that at least one modern compiler invokes the "char const*" version.
Any thoughts?
--
Frederick Gotham
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Ron Natalie
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| Posted: Wed Oct 04, 2006 2:40 am Post subject: Re: String literal pointer decay funkiness... |
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Frederick Gotham wrote:
| Quote: | The type of a string literal is:
char const[sizeof "whatever is written"]
|
This is true.
| Quote: | However, it decays to a pointer to non-const, rather than a pointer
to const. |
This is not true:
A string literal (2.13.4) that is not a wide string literal can be
converted to an rvalue of type “pointer to
char”; a wide string literal can be converted to an rvalue of type
“pointer to wchar_t”. In either case,
the result is a pointer to the first element of the array. This
conversion is considered only when there is an
explicit appropriate pointer target type, and not when there is a
general need to convert from an lvalue to an
rvalue. [Note: this conversion is deprecated. See Annex D. ] For the
purpose of ranking in overload resolution
(13.3.3.1.1), this conversion is considered an array-to-pointer
conversion followed by a qualification
conversion (4.4). [Example: "abc" is converted to “pointer to const
char” as an array-to-pointer conversion,
and then to “pointer to char” as a qualification conversion. ]
| Quote: | I would have thought that the "char*" version would be invoked, but it seems
that at least one modern compiler invokes the "char const*" version.
Why would you expect that? While the conversion to char* is permitted, |
the type is still char const[n] which would match preferentially the
char const* overload.
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