How to delete arbitrary objects in repeated field? (protobuf)

Question

I have some entries in the repeated field in my proto. Now I want delete some of them. How can I accomplish this? There is a function to delete the last element, but I want to d

Answer 1

Although there's no straight-forward method you still can do this (for custom message using reflection). Code below removes count repeated field items starting from row index.

void RemoveFromRepeatedField(
    const google::protobuf::Reflection *reflection,
    const google::protobuf::FieldDescriptor *field,
    google::protobuf::Message *message,
    int row,
    int count)
{
    int size = reflection->FieldSize(*message, field);
    // shift all remaining elements
    for (int i = row; i < size - count; ++i)
        reflection->SwapElements(message, field, i, i + count);
    // delete elements from reflection
    for (int i = 0; i < count; ++i)
        reflection->RemoveLast(message, field);
}