declaration does not declare anything : warning?

Question

#include 
#include 
#include 

int main()
{
    struct emp
    {
        struct address
        {
              int a;
             


        

Answer 1

Going to also throw this out there that this error may also show up if you don't properly forward declare types found in other namespaces.

https://stackoverflow.com/a/19001722/1330381

Example

namespace A {

// forward declarations
namespace X {
namespace Y {
class MyType;
}
}

namespace B {

class Foo() {
    void methodBar(const X::Y::MyType& mt);
}
}