Will `typedef enum {} t` allow scoped enum element identifiers in C++0x?
I believe the new C++ standard allows for an extra "scope" for enumerated types:
enum E { e1, e2 };
E var = E::e1;
Since I know lots of source files containing the old C-style enum typedef, I wondered if the new standard would allow using the typedef for these otherwise anonymous enum开发者_如何学编程erated types:
typedef enum { d1, d2 } D;
D var = D::d1; // error?
The new standard will add a new type of strong enum, but the syntax will be slightly different, and old style enums will be compatible (valid code in C++03 will be valid C++0x code) so you will not need to do anything to keep legacy code valid (not the typedef, not anything else).
enum class E { e1, e2 }; // new syntax, use E::e1
enum E2 { e1, e2 }; // old syntax, use e1 or E2::e1 (extension)
There is a C++ FAQ here that deals with this particular issue.
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