Is C code still considered C++?

Question

The comment to this answer got me wondering. I\'ve always thought that C was a proper subset of C++, that is, any valid C code is valid C++ code by extension. Am I wrong a

Answer 1

A few more:

C allows recursive calls to main, C++ does not

char foo[3] = "abc" is legal C, not C++

sizeof('A') == sizeof(int) is true in C and false in C++

There are even more changes with C99

Edit: I found a post that lists the majority of the differences. http://c-faq.com/misc/cplusplus.nr.html

Summary of why C is not proper subset of C++:

1. auto conversion from void * to any object/incomplete type
2. new keywords (a number of these)
3. due to structs becoming scoped
4. due to struct tags becoming typedefs
5. due to prototypes being required
6. implicit int rules
7. Recursive call to main
8. Due to // comments
9. due to character literals being type char and not int etc.