remove the tiny bit of unsafe code

These are left over from a series of unfortunate rustfmt interactions.
serde-rs@ee75e6c#diff-c052b162f01a664f8184ef1855d1f1cfL767-R735
serde-rs@cc2558b#diff-c052b162f01a664f8184ef1855d1f1cfL733-R738
serde-rs@9f38ca0#diff-c052b162f01a664f8184ef1855d1f1cfL779-R782

Allow #[serde(borrow)] for non-std Cow

Simplify default Serializer::collect_str implementation

Hide generated dummy const in rustdoc

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This one build always took several (10+) minutes on:

    Updating registry `https://github.com/rust-lang/crates.io-index`

Since this step takes the longest.

We don't run clippy on PRs. It is covered by a separate clippy.yml
workflow.

This picks up changes from a135199 and 1b35c9e.

This test isn't high enough signal to have all contributors run it.

Fix indexing bug when `skip` and `other` are combined

Let's keep impls.rs for Serialize impls, which there are enough of
already.

This allows formatter flags to take effect.

Serialize_newtype_struct is typically expected to just pass through the
wrapped value.

* Deserialize adjacently tagged newtype variants with optional content as None instead of erroring when content field is missing

* refactor to remove duplicate code and remove panic

    error[E0506]: cannot assign to `missing_content` because it is borrowed
        --> serde_derive/src/de.rs:1414:9
         |
    1388 |           .filter_map(|(i, variant)| {
         |                       -------------- borrow of `missing_content` occurs here
    ...
    1414 | /         missing_content = quote! {
    1415 | |             match __field {
    1416 | |                 #(#missing_content_arms)*
    1417 | |                 #missing_content_fallthrough
    1418 | |             }
    1419 | |         };
         | |_________^ assignment to borrowed `missing_content` occurs here

    error[E0502]: cannot borrow `missing_content_fallthrough` as immutable because it is also borrowed as mutable
        --> serde_derive/src/de.rs:1414:27
         |
    1388 |           .filter_map(|(i, variant)| {
         |                       -------------- mutable borrow occurs here
    ...
    1404 |                       missing_content_fallthrough = quote!(_ => #missing_content);
         |                       --------------------------- previous borrow occurs due to use of `missing_content_fallthrough` in closure
    ...
    1414 |           missing_content = quote! {
         |  ___________________________^
    1415 | |             match __field {
    1416 | |                 #(#missing_content_arms)*
    1417 | |                 #missing_content_fallthrough
    1418 | |             }
    1419 | |         };
         | |_________^ immutable borrow occurs here
    ...
    1622 |   }
         |   - mutable borrow ends here
         |
         = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

Add a CI builder on 1.31.0

Update 'Getting help' section

Look inside of None-delimited groups when examining types

Cargo.toml is always included in the published crate.

Clippy bug: rust-lang/rust-clippy#5704

Forward serialize_entry on flattened maps

Add FlexBuffers to serde ecosystem list

Add FlexBuffers to serde ecosystem list

Use underscore consts on Rust 1.37+

Remove len hint specialization

No longer seeing warnings on this from rustfmt.

    error: The usage of Script Group `Greek` in this crate consists solely of mixed script confusables
       --> test_suite/tests/test_gen.rs:269:9
        |
    269 |         σ: f64,
        |         ^
        |
    note: the lint level is defined here
       --> test_suite/tests/test_gen.rs:5:9
        |
    5   | #![deny(warnings)]
        |         ^^^^^^^^
        = note: `#[deny(mixed_script_confusables)]` implied by `#[deny(warnings)]`
        = note: The usage includes 'σ' (U+03C3).
        = note: Please recheck to make sure their usages are indeed what you want.

When building with beta and older rustc:

    error: unknown lint: `mixed_script_confusables`
     --> test_suite/tests/test_gen.rs:7:10
      |
    7 | #![allow(mixed_script_confusables, clippy::trivially_copy_pass_by_ref)]
      |          ^^^^^^^^^^^^^^^^^^^^^^^^
      |
    note: the lint level is defined here
     --> test_suite/tests/test_gen.rs:5:9
      |
    5 | #![deny(warnings)]
      |         ^^^^^^^^
      = note: `#[deny(unknown_lints)]` implied by `#[deny(warnings)]`

This test has multiple #[ignore] attributes in some configurations.

    $ cargo +beta check --test expandtest
    warning: unused attribute
     --> test_suite/tests/expandtest.rs:2:29
      |
    2 | #[cfg_attr(not(expandtest), ignore)]
      |                             ^^^^^^
      |
      = note: `#[warn(unused_attributes)]` on by default

Per https://github.com/serde-rs/serde#getting-help we're steering these
to Discord / Stack Overflow / Reddit / etc.

Can reconsider when GitHub Discussions is out of beta
(https://github.com/vercel/next.js/discussions).

Support flattening a Unit

Rename TyOverby/bincode to servo/bincode

Replace serde_urlencoded link with serde_qs

Automatically generated enum variant deserializers allowed any integer
type as the discriminant, but the hand-written ones for specific enum
types such as Result or IpAddr only allowed types up to u32. This broke
some non-human-readable deserializers for these enums, with
deserializers that emit any integer type as a u64. Switch the visit_u32
methods to visit_u64 methods to allow discriminants to have any size up
to a u64.

…zation-u64

Fix hand-written enum variant deserializations to allow u64 discriminant

rust-lang/rust#77426

Fix misprint in the error message

…ling)

…dentifiers deserialized with visit_u64

Thus behavior synchronized between string/bytes identifiers and numeric identifiers

…nt keys in serde_test

…ected by enum deserializer

Before that fix following code panics, because `Token::Unit` was unexpected by test deserializer:
```
#[derive(Deserialize)]
enum E { ... }

assert_de_tokens_error::<E>(&[Token::Unit], "...");
```

…ecting = "...")]`

Closes serde-rs#1883

It helps to create deserializers that can stop time: save the value and then use visitor to get it later!

…ierDeserializer

Serializer contains expected tokens, called methods provide actual tokens

…d instead of usage of default implementation

Difference is noticeable for deserializers that rely on call of next_entry_seed
(for example, current quick-xml supports only next_entry_seed)

    error: use `std::ptr::eq` when comparing raw pointers
       --> serde_derive/src/de.rs:362:12
        |
    362 |         if field as *const Field == transparent_field as *const Field {
        |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `std::ptr::eq(field, transparent_field)`
        |
    note: the lint level is defined here
       --> serde_derive/src/lib.rs:18:9
        |
    18  | #![deny(clippy::all, clippy::pedantic)]
        |         ^^^^^^^^^^^
        = note: `#[deny(clippy::ptr_eq)]` implied by `#[deny(clippy::all)]`
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_eq

… `assert_tokens` functions

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:1876:9
         |
    1876 | /         impl<'de> Deserialize<'de> for Field {
    1877 | |             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    1878 | |             where
    1879 | |                 D: Deserializer<'de>,
    ...    |
    1917 | |             }
    1918 | |         }
         | |_________^
         |
    note: the lint level is defined here
        --> serde/src/lib.rs:95:52
         |
    95   | #![cfg_attr(feature = "cargo-clippy", deny(clippy, clippy_pedantic))]
         |                                                    ^^^^^^^^^^^^^^^
         = note: `#[deny(clippy::items_after_statements)]` implied by `#[deny(clippy::pedantic)]`
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:1920:9
         |
    1920 |         struct DurationVisitor;
         |         ^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:1922:9
         |
    1922 | /         impl<'de> Visitor<'de> for DurationVisitor {
    1923 | |             type Value = Duration;
    1924 | |
    1925 | |             fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
    ...    |
    1979 | |             }
    1980 | |         }
         | |_________^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:1982:9
         |
    1982 |         const FIELDS: &'static [&'static str] = &["secs", "nanos"];
         |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:2001:9
         |
    2001 | /         impl<'de> Deserialize<'de> for Field {
    2002 | |             fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    2003 | |             where
    2004 | |                 D: Deserializer<'de>,
    ...    |
    2042 | |             }
    2043 | |         }
         | |_________^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:2045:9
         |
    2045 |         struct DurationVisitor;
         |         ^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:2047:9
         |
    2047 | /         impl<'de> Visitor<'de> for DurationVisitor {
    2048 | |             type Value = Duration;
    2049 | |
    2050 | |             fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
    ...    |
    2108 | |             }
    2109 | |         }
         | |_________^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

    error: adding items after statements is confusing, since items exist from the start of the scope
        --> serde/src/de/impls.rs:2111:9
         |
    2111 |         const FIELDS: &'static [&'static str] = &["secs_since_epoch", "nanos_since_epoch"];
         |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
         |
         = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#items_after_statements

Allow serializing of Wrapping without std

Add serde_dynamo to the list of data formats

Fixes a rustdoc warning:

    warning: unneeded long form for URL
      --> serde/src/lib.rs:12:27
       |
    12 | //! See the Serde website [https://serde.rs/] for additional documentation and
       |                           ^^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<https://serde.rs/>`
       |
       = note: `#[warn(non_autolinks)]` on by default

Both of these modules are doc(hidden) and commented "Not public API",
but incorrect downstream code sometimes still references them. Naming
the module __private will make it more likely to be noticed in code
review.

    error[E0432]: unresolved import `private::de::size_hint`
      --> src/de/value.rs:28:5
       |
    28 | use private::de::size_hint;
       |     ^^^^^^^^^^^^^^^^^^^^^^ Maybe a missing `extern crate private`?

Only refactors, doesn't actually expose this visitor

refactor: Merge multiple FromStr visitors to a single FromStrVisitor

This fixes the errors that occur when IgnoredAny is deserialized
from anything containing a 128-bit integer somewhere. As IgnoredAny
is used in serde_derive to skip ignored fields in structs, these
errors currently prevent parsing of structs with an ignored field
containing a 128-bit integer in the serialization.

Add 128-bit integer support to de::IgnoredAny

std::time::Duration::new can panic. There is no alternative non-panicing constructor.
Check the panic condition beforehand and return an error instead of panicing.

Fixes serde-rs#1933