example/cascade_echo_c++/echo.proto

syntax="proto2";
package example;

option cc_generic_services = true;

message EchoRequest {
    required string message = 1;
    optional int32 depth = 2;
};

message EchoResponse {
    required string message = 1;
};

service EchoService {
    rpc Echo(EchoRequest) returns (EchoResponse);
};