warning: accessing first element with `variant.fields.get(0)`
        --> serde_derive/src/de.rs:1843:27
         |
    1843 |             let default = variant.fields.get(0).map(|field| {
         |                           ^^^^^^^^^^^^^^^^^^^^^ help: try: `variant.fields.first()`
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_first
         = note: `-W clippy::get-first` implied by `-W clippy::all`
         = help: to override `-W clippy::all` add `#[allow(clippy::get_first)]`

    warning: accessing first element with `variant.fields.get(0)`
        --> serde_derive/src/de.rs:1888:27
         |
    1888 |             let default = variant.fields.get(0).map(|field| {
         |                           ^^^^^^^^^^^^^^^^^^^^^ help: try: `variant.fields.first()`
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_first

    warning: unused imports: `cmp`, `mem`, `slice`
       --> serde/src/lib.rs:171:26
        |
    171 |     pub use self::core::{cmp, iter, mem, num, ptr, slice, str};
        |                          ^^^        ^^^            ^^^^^
        |
        = note: `#[warn(unused_imports)]` on by default

Ensure f32 deserialized from f64 and vice versa preserve NaN sign