Notation for "reference to array" type

Question

In c++, type of a reference to array is shown like int (&) [10]. As an example, when I try to compile with g++ and clang the following code

template <typename T> void foo(T&);

int main() {
    int a[] {1, 2, 3};

    foo(a);
}

I get the following error:

undefined reference to `void foo<int [3]>(int (&) [3])'

In this error text, why is the type of argument shown as int (&) [3]? Why don't we denote array reference types like references to integral types or class types, i.e. int [10] &? What is the reason for using (&)?

I know we can define a 'reference to array' variable like this:

int (&b)[3] = a;

And this definition indeed 'looks like' the type of b. But is this the only reason? Is there a problem related to the notation int [10] &?

Answer 1

It comes from how the type of pointers to arrays look like: int(*)[10]. The * is just replaced by &, like in all reference types.

The reason that pointers to arrays look like that is how it looks like in C, and C++ had no reason to change it.

int (*a)[10];
// "(*a)[10]" is an int
// The type of `a` is `int (*)[10]`, just remove the name

I don't see any technical reasons why int[10]* and int[10]& would not be possible as the name of the types for "pointer or reference to an array of 10 int", other than compatibility with C