Why must I put a semicolon at the end of class declaration in C++?

Question

In a C++ class declaration:

class Thing
{
    ...
};

why must I include the semicolon?

Answer 1

Because it could be a definition of the next element. For example, taking it from C syntax: if you declare

struct { ... } main (int argc, char..

then it assumes main returns a struct. If there was a semicolon,

struct { ... }; main (int argc, char..

then main returns an int.