disambiguation rules (was: Deprecate the use of plain pointers as standard container iterators)
kuyper@wizard.net wrote:
Nicola Musatti wrote:
..
The following code gives different results on different platforms:
#include <vector>
#include <algorithm>
#include <iostream>
int * find(int * b, int * e, int d) {
return b + d < e ? b + d : e;
}
int main() {
std::vector<int> v;
v.push_back(3);
v.push_back(2);
v.push_back(1);
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.
"Doctor, it hurts when I hit myself in the head with a hammer."
"Then stop hitting yourself in the head with a hammer."
Use std::find(), if you want to make sure that it's actually
std::find() that you're calling. If you actually want the compiler to
consider other possible overloads, make sure that any other overload
that could be selected has acceptable semantics, and doesn't lead to
ambiguity as to which overload should be selected. This is the same
advice that applies whenever calling any function; there's nothing
special about the fact that v.begin() might (or might not) be a
pointer.
..
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?
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