C and C++ difference in sizeof('x')

Question

Possible Duplicate:
Why are C character literals ints instead of chars?

Why when using C does sizeof('x') return 4 but sizeof('x') in C++ returns 1?

C++ normally strives to be nothing more than a superset of C so why do the two results diverge?

Edit Just some further clarification. This seems like a deliberate move on the part of the standards committee and I assume changing the size of 'x' would not have been done without a good reason. I am interested in what the reason is.

Answer 1

Because is C, 'x' is actually an int, while in C++ it's a char.

C++ tries is tighten up strong typing that was a bit lax in C.

Answer 2

C++ is not a superset of C. Particularly if you use the "current" versions - a compiler in C++0x mode will choke on C99 code.

Answer 3

To quote the C++ standard ISO 14882:2003, annex C.1.1 clause 2.13.2

Change: Type of character literal is changed from int to char

Rationale: This is needed for improved overloaded function argument type matching. For example:

int function( int i );
int function( char c );
function( ’x’ );

It is preferable that this call match the second version of function rather than the first

(annex C describes the incompatibilities between C and C++)