Constraint template function parameter types

Question

There are two insert functions, defined as follows

template<typename T, typename Allocator>
auto list<T, Allocator>::insert(iterator pos, size_t count, const T & value)->iterator
{
    for (size_t i = 0; i < count; i++) {
        pos = insert(pos, value);
    }
    return pos;
}


template<typename T, typename Allocator>
template<typename InputIt>
 auto list<T, Allocator>::insert(iterator pos, InputIt first, InputIt last) -> iterator
{
     for (InputIt iter = first; iter != last; ++iter) {
         pos = insert(pos, *iter);// Indirection operator ( * ) is applied to a nonpointer value.
     }
    return pos;
}

When the type of T is int,The following call to insert will cause an error

list<int> l1;
l1.insert(l1.begin(),10, 2);//cause error

Because the second insert function can be matched more accurately than the first (no conversion required)

Is there any way to limit the type of InputIt? This function can only be matched when there is a certain type in InputIt

What exactly is the problem? https://godbolt.org/z/sh7jsc6ef — Joseph Sible-Reinstate Monica, Jul 01 '21 at 03:21
The problem is that l1.insert(l1.begin(),10, 2) calls the second insert function, InputIt is deduced into int, but int cannot be dereferenced — clay, Jul 01 '21 at 03:52
Did you look at the link I posted? Isn't that evidence that what you're saying happens doesn't actually happen? — Joseph Sible-Reinstate Monica, Jul 01 '21 at 03:53
In that case, can you post a minimal, reproducible example, i.e., a complete program that I can copy and paste with no changes, that will demonstrate the problem when I try it? What you posted is missing the class declaration among other things. — Joseph Sible-Reinstate Monica, Jul 01 '21 at 03:56
Or this? [How does a compiler distinguish between two variations of “vector::insert”?](https://stackoverflow.com/q/45581142/7509065) Or this? [Own vector assign implementation](https://stackoverflow.com/q/61889111/7509065) — Joseph Sible-Reinstate Monica, Jul 01 '21 at 04:07

Constraint template function parameter types

0 Answers0