Not found the implements of MapRow for closure

[wyanlord]

    let sql = "select id, username from t_user where id < ?";
    let mut stream = sqlx::query(sql).bind(3_i32).
        map::<_, User>(|row: MySqlRow| {
            Ok(User {
                id: row.get("id"),
                username: row.get("username"),
            })
        }).fetch(&pool);

    while let Some(user) = stream.next().await? {
        println!("{:?}", user);
    }

error[E0277]: the trait bound `[closure@src\main.rs:36:24: 41:10]: sqlx_core::query::MapRow<sqlx_core::mysql::database::MySql>` is not satisfied
  --> src\main.rs:36:9
   |
36 |         map::<_, User>(|row: MySqlRow| {
   |         ^^^ the trait `sqlx_core::query::MapRow<sqlx_core::mysql::database::MySql>` is not implemented for `[closure@src\main.rs:36:24: 41:10]`