BSON likes Strings and hates u32/usize

[TrionProg]

Hello. I have struct

pub struct Award{
    pub name:String,
    pub icon:Uuid,
    pub description:String,
    pub id:String,
}

And I write it to mongodb

                let award=Award{
                //id:id as u32,
                name:String::from(award_name),
                icon:icon,
                description:description,
                id:id .to_string(),
            };

            let serialized_award = bson::to_bson(&award)?;

            let find_filter=doc! {
                "_id" => user_id
            };

            let update_doc=doc! {//All right?
                "$push" => { "awards" => serialized_award }
            };

            mongo_users.find_one_and_update( find_filter ,update_doc, None );//TODO:None

And later I read:

let doc=mongo_users.find_one(Some(find_filter),Some(find_option))?;

        println!("{:?}",doc);

        match doc {
            Some( doc ) => {
               match doc.get("awards") {
                Some(&Bson::Array(ref mongo_awards)) => {

                let mut awards=Vec::with_capacity(mongo_awards.len());
                for mongo_award in mongo_awards.iter() {
                    match *mongo_award {
                        Bson::Document( ref doc ) => {
                            let award:Award = bson::from_bson( bson::Bson::Document(doc.clone()) ).unwrap();//NOTE : problem, and I DO NOT WANT CLONE document!

Part of mongo document

"awards": Array([Document({ name: "abc", icon: "a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11", description: "def", id: 1 })])

If id of struct Award is String, all works, but if id is u32 or usize I get InvalidType("u32")
Note that Display trait for this error writes only usize,u32 without any description like InvalidType:usize

UPD. Struct initialization in exemple gets &'static str instead String. This code do not works!

#[derive(Serialize, Deserialize, Debug)]
        pub struct Person {
            #[serde(rename = "_id")]  // Use MongoDB's special primary key field name when serializing
            pub id: String,
            pub name: String,
            pub age: u32
        }

        let person = Person {
            id: "12345".to_string(),
            name: "Emma".to_string(),
            age: 3
        };

        let serialized_person = bson::to_bson(&person)?;  // Serialize

        let person2:Person = bson::from_bson(serialized_person).unwrap();
}

Cargo.toml

serde="1.0.2"
serde_derive="*"
bincode="*"
redis = "*"
cdrs = "1.0.0-rc.1"
bson = ">=0.7.0"
mongodb = ">=0.2.7"

i32,i64 works. I guess, bson hates unsigned types.

[zonyitoo]

I can reproduce your error in my environment.

the serialized_person in your example is actually something like this:

Document(OrderedDocument({"_id": String("12345"), "name": String("Emma"), "age": FloatingPoint(3)}))

As you can see, age is a FloatingPoint. So why it is serialized to a FloatingPoint instead of a I32? ... Hmm...

The problem is that BSON doesn't support unsigned type.