Re: disambiguation rules (was: Deprecate the use of plain pointers as standard container iterators)

From:

"Nicola Musatti" <nicola.musatti@gmail.com>

Newsgroups:

comp.std.c++

Date:

Mon, 8 May 2006 11:24:28 CST

Message-ID:

<1147087582.355054.224260@j73g2000cwa.googlegroups.com>

wkaras@yahoo.com wrote:

kuyper@wizard.net wrote:

Nicola Musatti wrote:

[...]

int * find(int * b, int * e, int d) {
return b + d < e ? b + d : e;
}

int main() {
std::vector<int> v;

// ...

std::vector<int>::iterator i = find(v.begin(), v.end(), 2);
std::cout << ( i != v.end() ? *i : 0 ) << '\n';
}

If std::vector<>::iterator is a pointer the user defined find function
is chosen.

[...]

In this example, it's clear that it would be better if the function
from the namespace implied by the parameter took precedence
over the function in the namespace of the call. What is the
rational for the order of precedence?

Non templated functions always take precedence over templated ones,
which in general it is reasonable as the former can be seen as
conceptual specializations of the latter. In fact the real problem of
my (contrived) example is the fact that my own find is misnomed.

It is still an example of the traps laid out for the unaware within the
most basic elements of the standard library.

Cheers,
Nicola Musatti

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