oneof fields are not handled properly

[mechterp10]

Example

Input

syntax = "proto3";

package test;

message SubType {
    enum Type {
        TYPE_1 = 0;
        TYPE_2 = 1;
    }

    Type field_1 = 1;
    uint64 field_2 = 2;

    oneof OneOfField {
        int32 field_3 = 3;
        double field_6 = 6;
    }
}

Output

syntax = "proto3";
namespace test {
struct SubType {
enum Type {
TYPE_1 = 0,
TYPE_2 = 1,
};
Type field_1 = 1;
uint64 field_2 = 2;
oneof OneOfField {
int32 field_3 = 3;
double field_6 = 6;
};
};
}

In documentation, one would expect that field_3 could be referenced as test::SubType::field_3 or test::SubType::OneOfField::field_3. However, the field is not accessible as oneof is not a C++ type.

Once the style is chosen (i.e, test::SubType3::field_3 or test::SubType3::OneOfField::field_3) the fix is relatively simple.