strong typing - Is C++ considered weakly typed? Why?

Question

I've always considered C++ to be one of the most strongly typed languages out there.
So I was quite shocked to see Table 3 of this paper state that C++ is weakly typed.

Apparently,

C and C++ are considered weakly typed since, due to type-casting, one can interpret a field of a structure that was an integer as a pointer.

Is the existence of type casting all that matters? Does the explicit-ness of such casts not matter?

More generally, is it really generally accepted that C++ is weakly typed? Why?

Answer 1

That paper first claims:

In contrast, a language is weakly-typed if type-confusion can occur silently (undetected), and eventually cause errors that are difficult to localize.

And then claims:

Also, C and C++ are considered weakly typed since, due to type-casting, one can interpret a field of a structure that was an integer as a pointer.

This seems like a contradiction to me. In C and C++, the type-confusion that can occur as a result of casts will not occur silently -- there's a cast! This does not demonstrate that either of those languages is weakly-typed, at least not by the definition in that paper.

That said, by the definition in the paper, C and C++ may still be considered weakly-typed. There are, as noted in the comments on the question already, cases where the language supports implicit type conversions. Many types can be implicitly converted to bool, a literal zero of type int can be silently converted to any pointer type, there are conversions between integers of varying sizes, etc, so this seems like a good reason to consider C and C++ weakly-typed for the purposes of the paper.

For C (but not C++), there are also more dangerous implicit conversions that are worth mentioning:

int main() {
  int i = 0;
  void *v = &i;
  char *c = v;
  return *c;
}

For the purposes of the paper, that must definitely be considered weakly-typed. The reinterpretation of bits happens silently, and can be made far worse by modifying it to use completely unrelated types, which has silent undefined behaviour that typically has the same effect as reinterpreting bits, but blows up in mysterious yet sometimes amusing ways when optimisations are enabled.

In general, though, I think there isn't a fixed definition of "strongly-typed" and "weakly-typed". There are various grades, a language that is strongly-typed compared to assembly may be weakly-typed compared to Pascal. To determine whether C or C++ is weakly-typed, you first have to ask what you want weakly-typed to mean.