Rust converting a struct to key value pair where the field is not none

Question

I have a struct generated by prost (protobuf implementation based on proto).

pub struct Data {
    #[prost(string, tag="1")]
    pub field1: ::prost::alloc::string::String,
    #[prost(message, optional, tag="2")]
    pub struct_2: ::core::option::Option<Struct2>,
    #[prost(message, optional, tag="3")]
    pub struct_3: ::core::option::Option<Struct3>,
    #[prost(string, tag="4")]
    pub test_param: ::prost::alloc::string::String,
}

I am able to decode the protobuf data from the above.

The catch is I receive some fields which are none in the above struct. only some fields are filled at any given time.

eg:

Data { field1: "testfield", struct_2: None, struct_3: None, test_param: "test" }

I want to be able to:

select only non-none values from the struct.
Iterate over them and put them as a key value pair.

Eg:

let keyvalue = Hashmap::new()
for k,v in buffered_data.to_vector().iter() {
  if k.IsSome(){
    keyvalue.insert("k",v)   
  }
}

expected output would be something like:

keyvalue:
{
"field1":"test_field",
"test_param": "test"
}

I am receiving the info as serialized proto bytes and I can decode them to prost structs, — Abhilash Gopalakrishna, Aug 02 '22 at 11:05
I mean, why not just do `map.insert("field1", v.field1); if let Some(field2) = v.field2 { map.insert("field2", field2); }` etc.? — Chayim Friedman, Aug 02 '22 at 11:26
makes sense for short structs, but my struct is really large .i.e it can have upto 100 fields, so an iterator makes sense, is what I am thinking. — Abhilash Gopalakrishna, Aug 02 '22 at 11:31
An iterator must have one type, so this is generally impossible (a map too). — Chayim Friedman, Aug 02 '22 at 11:38
Found this: https://crates.io/crates/structmap. May be helpful. — Chayim Friedman, Aug 02 '22 at 11:39
You should clarify what you mean by "put them as a key value pair". Do you want a `Vec<(String, String)>`? Or a `HashMap`? Or do you want a json? The tools you would use are very different. — cyqsimon, Mar 29 '23 at 17:35

Rust converting a struct to key value pair where the field is not none

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