Why is swapping multidimensional arrays not noexcept?

Question

I have the following snippet:

#include 
#include 

int main(int argc, char** argv) {
    int x[2][3];
    int y[2][3];

    usin         


        

Answer 1

This overload:

template<class T, size_t N>
void swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));

is not in scope until ;, so swap(*a, *b) doesn't consider this overload. This is because of:

3.3.2/1 The point of declaration for a name is immediately after its complete declarator (Clause 8) and before its initializer (if any) …

and the exception specification is part of the declarator.