Annex C (informative) Compatibility [diff]

C.2 C++ and ISO C++ 2003 [diff.cpp03]

C.2.2 [expr]: expressions [diff.cpp03.expr]

Affected subclause: [conv.ptr]
Change: Only literals are integer null pointer constants.

Rationale: Removing surprising interactions with templates and constant expressions.

Effect on original feature: Valid C++ 2003 code may fail to compile or produce different results in this International Standard.
For example:
void f(void *);  // #1
void f(...);     // #2
template<int N> void g() {
  f(0*N);        // calls #2; used to call #1
}
Affected subclause: [expr.mul]
Change: Specify rounding for results of integer / and %.

Rationale: Increase portability, C99 compatibility.

Effect on original feature: Valid C++ 2003 code that uses integer division rounds the result toward 0 or toward negative infinity, whereas this International Standard always rounds the result toward 0.
Affected subclause: [expr.log.and]
Change: && is valid in a type-name.

Rationale: Required for new features.

Effect on original feature: Valid C++ 2003 code may fail to compile or produce different results in this International Standard.
For example:
bool b1 = new int && false;           // previously false, now ill-formed
struct S { operator int(); };
bool b2 = &S::operator int && false;  // previously false, now ill-formed