when i compiled a proto file with a map, occer error

[ghost]

use protoc-2.6.1-win32/protoc.exe

proto file :

message Config { 
    map<string, string> biyun_levels = 1;
}

error:

config.proto:5:5: Expected "required", "optional", or "repeated".
config.proto:5:8: Expected field name.

in the doucment, it says protobuf2 supports Maps, but this error is why?

[xfxyjwf]

The maps syntax is only supported starting from v3.0.0. The "proto2" in the doc is referring to the syntax version, not protobuf release version. v3.0.0 supports both proto2 syntax and proto3 syntax while v2.6.1 only supports proto2 syntax. For all users, it's recommended to use v3.0.0-beta-1 instead of v2.6.1.

[LazyPlanet]

The generated map API is currently available for all proto2 supported languages. You can find out more about the map API for your chosen language in the relevant API reference.

[LazyPlanet]

does 2.6.1 support map?