Why are vector's multi-argument constructors taking construction parameters not marked "explicit"?

I observed the following vector constructors in the Standard C++ library

explicit vector(size_type n);
vector(size_type n, const T& value, const Allocator& = Allocator());

Is there a reason why the second constructor is not marked explicit? This compiles, and makes me feel bad

void f(vector<string>);

int main() {
  f({10, "foo"});
}

While if I omit the "foo", it doesn't compile and that is what I expect when I pass a pair (compound) value of an int and a string to a function that wants a vector of strings.