The ISO C++ committee met in Toronto on July 15-20. This is a list of features that was voted into the C++0x draft.

enum class (N2347)

• enumerators are in the scope of their enum
• enumerators and enums do not implicitly convert to int
• enums have a defined underlying type
• backward-compatible

The new enum type is declared using enum class, which does not conflict with existing enums:

enum class E{ E1, E2, E3 = 100, E4 /* = 101 */ };

There is no implicit conversion to or from an integer:

enum class E{ E1, E2, E3 = 100, E4 /* = 101 */ };

void f(E e) {
    if( e >= 100 )      // error: no E to int conversion
        ;
}

int i = E::E2;          // error: no E to int conversion

Like a class, the new enum type introduces its own scope.

enum class E{ E1, E2, E3 = 100, E4 /* = 101 */ };

E e1 = E1;      // error
E e2 = E::E2;   // ok

Document: N2347

Saving exceptions (N2179)

Adds language and library support for saving an exception.

//In: <exception>

namespace std {

    typedef unspecified exception_ptr;

    exception_ptr current_exception();
    void rethrow_exception( exception_ptr p );

    template< class E > exception_ptr copy_exception( E e );

}

Document: N2179

constexpr (N2235 and N2349)

This language feature permits generalized constant expressions:

constexpr int add(int a, int b)
{
    return a + b;
}

Now if you call add() with two compile-time constants, then the result of calling add() is still a compile-time constant.

int arr[ add(1, 2) ];

Document: N2235 and N2349