Function protobuf::reflect::accessor::make_singular_ptr_field_accessor

pub fn make_singular_ptr_field_accessor<M, V>(name: &'static str,
                                              get_field: fn<'a>(_: &'a M) -> &'a SingularPtrField<V::Value>,
                                              mut_field: fn<'a>(_: &'a mut M) -> &'a mut SingularPtrField<V::Value>)
                                              -> Box<FieldAccessor + 'static> where M: Message + 'static, V: ProtobufType + 'static