“Default member initializer needed within definition of enclosing class outside of member functions” - is my code ill-formed?

Question

#include 

struct foo
{
    int x{0};
    foo() noexcept = default;
    void f() noexcept(noexcept(std::declval())) {}
};

int main()
         


        

Answer 1

This is correct syntactical way is I can say.

#include 

struct foo
{
    int x{0};
    foo() noexcept {} // = default;
    void f() noexcept(noexcept(std::declval())) {}
};

int main()
{ 
}