Annex C (informative) Compatibility [diff]

C.4 C++ and ISO C++ 2014 [diff.cpp14]

C.4.4 Clause [dcl.decl]: declarators [diff.cpp14.decl]

[dcl.fct]
Change: Make exception specifications be part of the type system.
Rationale: Improve type-safety.
Effect on original feature: Valid C++ 2014 code may fail to compile or change meaning in this International Standard:

void g1() noexcept;
void g2();
template<class T> int f(T *, T *);
int x = f(g1, g2);    // ill-formed; previously well-formed

[dcl.init.aggr]
Change: Definition of an aggregate is extended to apply to user-defined types with base classes.
Rationale: To increase convenience of aggregate initialization.
Effect on original feature: Valid C++ 2014 code may fail to compile or produce different results in this International Standard; initialization from an empty initializer list will perform aggregate initialization instead of invoking a default constructor for the affected types:

struct derived;
struct base {
  friend struct derived;
private: 
  base();
};
struct derived : base {};

derived d1{};       // Error. The code was well-formed before.
derived d2;         // still OK