c++ - Does curly brackets matter for empty constructor?

I'm wondering if the following constructors are the same for C++:

class foo
{ 
public:

   foo(void){};
...
}

and

class foo
{
public:

   foo(void);
...
}

Do curly brackets matter for these two cases? Thanks much!

Answer

They're not same. {} represents a regular function-body and makes the former function definition.

foo(void){}; // function definition

foo(void);   // function declaration