Enum variant collisions

[tomjakubowski]

A protobuf file like this:

message MessageA {
  enum EnumA { FOO = 0; }
}
message MessageB {
  enum EnumB { FOO = 0; }
}

generates Rust like:

#[deriving(Clone,Eq,Show)]
pub enum MessageA_EnumA {
    FOO = 0,
}

#[deriving(Clone,Eq,Show)]
pub enum MessageB_EnumB {
    FOO = 0,
}

Since Rust doesn't have scoped enums (and won't until after 1.0), a workaround for this might be to place protobuf messages into their own Rust modules. protoc enforces that enum values must be unique within messages, e.g. this:

message MessageA {
  enum EnumA { FOO = 0; }
  enum EnumB { FOO = 0; }
}

fails to compile with:

foo.proto:3:18: "FOO" is already defined in "MessageA".
foo.proto:3:18: Note that enum values use C++ scoping rules, meaning that enum values are siblings of their type, not children of it.  Therefore, "FOO" must be unique within "MessageA", not just within "EnumB".

[stepancheg]

@tomjakubowski fixed in db55952, thanks!