Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

2 files changed, 989 insertions, 0 deletions

diff --git a/third_party/rust/num-derive/src/lib.rs b/third_party/rust/num-derive/src/lib.rs
new file mode 100644
index 0000000000..ef55e4b0df
--- /dev/null
+++ b/third_party/rust/num-derive/src/lib.rs
@@ -0,0 +1,958 @@
+// Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "proc-macro"]
+#![doc(html_root_url = "https://docs.rs/num-derive/0.3")]
+#![recursion_limit = "512"]
+
+//! Procedural macros to derive numeric traits in Rust.
+//!
+//! ## Usage
+//!
+//! Add this to your `Cargo.toml`:
+//!
+//! ```toml
+//! [dependencies]
+//! num-traits = "0.2"
+//! num-derive = "0.3"
+//! ```
+//!
+//! Then you can derive traits on your own types:
+//!
+//! ```rust
+//! #[macro_use]
+//! extern crate num_derive;
+//!
+//! #[derive(FromPrimitive, ToPrimitive)]
+//! enum Color {
+//!     Red,
+//!     Blue,
+//!     Green,
+//! }
+//! # fn main() {}
+//! ```
+//!
+//! ## Explicit import
+//!
+//! By default the `num_derive` procedural macros assume that the
+//! `num_traits` crate is a direct dependency. If `num_traits` is instead
+//! a transitive dependency, the `num_traits` helper attribute can be
+//! used to tell `num_derive` to use a specific identifier for its imports.
+//!
+//! ```rust
+//! #[macro_use]
+//! extern crate num_derive;
+//! // Lets pretend this is a transitive dependency from another crate
+//! // reexported as `some_other_ident`.
+//! extern crate num_traits as some_other_ident;
+//!
+//! #[derive(FromPrimitive, ToPrimitive)]
+//! #[num_traits = "some_other_ident"]
+//! enum Color {
+//!     Red,
+//!     Blue,
+//!     Green,
+//! }
+//! # fn main() {}
+//! ```
+
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use proc_macro2::{Span, TokenStream as TokenStream2};
+use quote::quote;
+use syn::{Data, Fields, Ident};
+
+/// Try to parse the tokens, or else return a compilation error
+/// suggesting "full-syntax" if that's not already enabled.
+macro_rules! parse {
+    ($tokens:ident as $type:ty) => {
+        match syn::parse::<$type>($tokens) {
+            Ok(parsed) => parsed,
+            Err(mut error) => {
+                if cfg!(not(feature = "full-syntax")) {
+                    let hint = syn::Error::new(
+                        Span::call_site(),
+                        r#"this might need the "full-syntax" feature of `num-derive`"#,
+                    );
+                    error.combine(hint);
+                }
+                return TokenStream::from(error.to_compile_error());
+            }
+        }
+    };
+}
+
+// Within `exp`, you can bring things into scope with `extern crate`.
+//
+// We don't want to assume that `num_traits::` is in scope - the user may have imported it under a
+// different name, or may have imported it in a non-toplevel module (common when putting impls
+// behind a feature gate).
+//
+// Solution: let's just generate `extern crate num_traits as _num_traits` and then refer to
+// `_num_traits` in the derived code.  However, macros are not allowed to produce `extern crate`
+// statements at the toplevel.
+//
+// Solution: let's generate `mod _impl_foo` and import num_traits within that.  However, now we
+// lose access to private members of the surrounding module.  This is a problem if, for example,
+// we're deriving for a newtype, where the inner type is defined in the same module, but not
+// exported.
+//
+// Solution: use the dummy const trick.  For some reason, `extern crate` statements are allowed
+// here, but everything from the surrounding module is in scope.  This trick is taken from serde.
+fn dummy_const_trick(trait_: &str, name: &Ident, exp: TokenStream2) -> TokenStream2 {
+    let dummy_const = Ident::new(
+        &format!("_IMPL_NUM_{}_FOR_{}", trait_, unraw(name)),
+        Span::call_site(),
+    );
+    quote! {
+        #[allow(non_upper_case_globals, unused_qualifications)]
+        const #dummy_const: () = {
+            #[allow(clippy::useless_attribute)]
+            #[allow(rust_2018_idioms)]
+            extern crate num_traits as _num_traits;
+            #exp
+        };
+    }
+}
+
+fn unraw(ident: &Ident) -> String {
+    ident.to_string().trim_start_matches("r#").to_owned()
+}
+
+// If `data` is a newtype, return the type it's wrapping.
+fn newtype_inner(data: &syn::Data) -> Option<syn::Type> {
+    match *data {
+        Data::Struct(ref s) => {
+            match s.fields {
+                Fields::Unnamed(ref fs) => {
+                    if fs.unnamed.len() == 1 {
+                        Some(fs.unnamed[0].ty.clone())
+                    } else {
+                        None
+                    }
+                }
+                Fields::Named(ref fs) => {
+                    if fs.named.len() == 1 {
+                        panic!("num-derive doesn't know how to handle newtypes with named fields yet. \
+                           Please use a tuple-style newtype, or submit a PR!");
+                    }
+                    None
+                }
+                _ => None,
+            }
+        }
+        _ => None,
+    }
+}
+
+struct NumTraits {
+    import: Ident,
+    explicit: bool,
+}
+
+impl quote::ToTokens for NumTraits {
+    fn to_tokens(&self, tokens: &mut TokenStream2) {
+        self.import.to_tokens(tokens);
+    }
+}
+
+impl NumTraits {
+    fn new(ast: &syn::DeriveInput) -> Self {
+        // If there is a `num_traits` MetaNameValue attribute on the input,
+        // retrieve its value, and use it to create an `Ident` to be used
+        // to import the `num_traits` crate.
+        for attr in &ast.attrs {
+            if let Ok(syn::Meta::NameValue(mnv)) = attr.parse_meta() {
+                if mnv.path.is_ident("num_traits") {
+                    if let syn::Lit::Str(lit_str) = mnv.lit {
+                        return NumTraits {
+                            import: syn::Ident::new(&lit_str.value(), lit_str.span()),
+                            explicit: true,
+                        };
+                    } else {
+                        panic!("#[num_traits] attribute value must be a str");
+                    }
+                }
+            }
+        }
+
+        // Otherwise, we'll implicitly import our own.
+        NumTraits {
+            import: Ident::new("_num_traits", Span::call_site()),
+            explicit: false,
+        }
+    }
+
+    fn wrap(&self, trait_: &str, name: &Ident, output: TokenStream2) -> TokenStream2 {
+        if self.explicit {
+            output
+        } else {
+            dummy_const_trick(trait_, &name, output)
+        }
+    }
+}
+
+/// Derives [`num_traits::FromPrimitive`][from] for simple enums and newtypes.
+///
+/// [from]: https://docs.rs/num-traits/0.2/num_traits/cast/trait.FromPrimitive.html
+///
+/// # Examples
+///
+/// Simple enums can be derived:
+///
+/// ```rust
+/// # #[macro_use]
+/// # extern crate num_derive;
+///
+/// #[derive(FromPrimitive)]
+/// enum Color {
+///     Red,
+///     Blue,
+///     Green = 42,
+/// }
+/// # fn main() {}
+/// ```
+///
+/// Enums that contain data are not allowed:
+///
+/// ```compile_fail
+/// # #[macro_use]
+/// # extern crate num_derive;
+///
+/// #[derive(FromPrimitive)]
+/// enum Color {
+///     Rgb(u8, u8, u8),
+///     Hsv(u8, u8, u8),
+/// }
+/// # fn main() {}
+/// ```
+///
+/// Structs are not allowed:
+///
+/// ```compile_fail
+/// # #[macro_use]
+/// # extern crate num_derive;
+/// #[derive(FromPrimitive)]
+/// struct Color {
+///     r: u8,
+///     g: u8,
+///     b: u8,
+/// }
+/// # fn main() {}
+/// ```
+#[proc_macro_derive(FromPrimitive, attributes(num_traits))]
+pub fn from_primitive(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = if let Some(inner_ty) = newtype_inner(&ast.data) {
+        quote! {
+            impl #import::FromPrimitive for #name {
+                #[inline]
+                fn from_i64(n: i64) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_i64(n).map(#name)
+                }
+                #[inline]
+                fn from_u64(n: u64) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_u64(n).map(#name)
+                }
+                #[inline]
+                fn from_isize(n: isize) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_isize(n).map(#name)
+                }
+                #[inline]
+                fn from_i8(n: i8) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_i8(n).map(#name)
+                }
+                #[inline]
+                fn from_i16(n: i16) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_i16(n).map(#name)
+                }
+                #[inline]
+                fn from_i32(n: i32) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_i32(n).map(#name)
+                }
+                #[inline]
+                fn from_i128(n: i128) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_i128(n).map(#name)
+                }
+                #[inline]
+                fn from_usize(n: usize) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_usize(n).map(#name)
+                }
+                #[inline]
+                fn from_u8(n: u8) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_u8(n).map(#name)
+                }
+                #[inline]
+                fn from_u16(n: u16) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_u16(n).map(#name)
+                }
+                #[inline]
+                fn from_u32(n: u32) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_u32(n).map(#name)
+                }
+                #[inline]
+                fn from_u128(n: u128) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_u128(n).map(#name)
+                }
+                #[inline]
+                fn from_f32(n: f32) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_f32(n).map(#name)
+                }
+                #[inline]
+                fn from_f64(n: f64) -> Option<Self> {
+                    <#inner_ty as #import::FromPrimitive>::from_f64(n).map(#name)
+                }
+            }
+        }
+    } else {
+        let variants = match ast.data {
+            Data::Enum(ref data_enum) => &data_enum.variants,
+            _ => panic!(
+                "`FromPrimitive` can be applied only to enums and newtypes, {} is neither",
+                name
+            ),
+        };
+
+        let from_i64_var = quote! { n };
+        let clauses: Vec<_> = variants
+            .iter()
+            .map(|variant| {
+                let ident = &variant.ident;
+                match variant.fields {
+                    Fields::Unit => (),
+                    _ => panic!(
+                        "`FromPrimitive` can be applied only to unitary enums and newtypes, \
+                         {}::{} is either struct or tuple",
+                        name, ident
+                    ),
+                }
+
+                quote! {
+                    if #from_i64_var == #name::#ident as i64 {
+                        Some(#name::#ident)
+                    }
+                }
+            })
+            .collect();
+
+        let from_i64_var = if clauses.is_empty() {
+            quote!(_)
+        } else {
+            from_i64_var
+        };
+
+        quote! {
+            impl #import::FromPrimitive for #name {
+                #[allow(trivial_numeric_casts)]
+                #[inline]
+                fn from_i64(#from_i64_var: i64) -> Option<Self> {
+                    #(#clauses else)* {
+                        None
+                    }
+                }
+
+                #[inline]
+                fn from_u64(n: u64) -> Option<Self> {
+                    Self::from_i64(n as i64)
+                }
+            }
+        }
+    };
+
+    import.wrap("FromPrimitive", &name, impl_).into()
+}
+
+/// Derives [`num_traits::ToPrimitive`][to] for simple enums and newtypes.
+///
+/// [to]: https://docs.rs/num-traits/0.2/num_traits/cast/trait.ToPrimitive.html
+///
+/// # Examples
+///
+/// Simple enums can be derived:
+///
+/// ```rust
+/// # #[macro_use]
+/// # extern crate num_derive;
+///
+/// #[derive(ToPrimitive)]
+/// enum Color {
+///     Red,
+///     Blue,
+///     Green = 42,
+/// }
+/// # fn main() {}
+/// ```
+///
+/// Enums that contain data are not allowed:
+///
+/// ```compile_fail
+/// # #[macro_use]
+/// # extern crate num_derive;
+///
+/// #[derive(ToPrimitive)]
+/// enum Color {
+///     Rgb(u8, u8, u8),
+///     Hsv(u8, u8, u8),
+/// }
+/// # fn main() {}
+/// ```
+///
+/// Structs are not allowed:
+///
+/// ```compile_fail
+/// # #[macro_use]
+/// # extern crate num_derive;
+/// #[derive(ToPrimitive)]
+/// struct Color {
+///     r: u8,
+///     g: u8,
+///     b: u8,
+/// }
+/// # fn main() {}
+/// ```
+#[proc_macro_derive(ToPrimitive, attributes(num_traits))]
+pub fn to_primitive(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = if let Some(inner_ty) = newtype_inner(&ast.data) {
+        quote! {
+            impl #import::ToPrimitive for #name {
+                #[inline]
+                fn to_i64(&self) -> Option<i64> {
+                    <#inner_ty as #import::ToPrimitive>::to_i64(&self.0)
+                }
+                #[inline]
+                fn to_u64(&self) -> Option<u64> {
+                    <#inner_ty as #import::ToPrimitive>::to_u64(&self.0)
+                }
+                #[inline]
+                fn to_isize(&self) -> Option<isize> {
+                    <#inner_ty as #import::ToPrimitive>::to_isize(&self.0)
+                }
+                #[inline]
+                fn to_i8(&self) -> Option<i8> {
+                    <#inner_ty as #import::ToPrimitive>::to_i8(&self.0)
+                }
+                #[inline]
+                fn to_i16(&self) -> Option<i16> {
+                    <#inner_ty as #import::ToPrimitive>::to_i16(&self.0)
+                }
+                #[inline]
+                fn to_i32(&self) -> Option<i32> {
+                    <#inner_ty as #import::ToPrimitive>::to_i32(&self.0)
+                }
+                #[inline]
+                fn to_i128(&self) -> Option<i128> {
+                    <#inner_ty as #import::ToPrimitive>::to_i128(&self.0)
+                }
+                #[inline]
+                fn to_usize(&self) -> Option<usize> {
+                    <#inner_ty as #import::ToPrimitive>::to_usize(&self.0)
+                }
+                #[inline]
+                fn to_u8(&self) -> Option<u8> {
+                    <#inner_ty as #import::ToPrimitive>::to_u8(&self.0)
+                }
+                #[inline]
+                fn to_u16(&self) -> Option<u16> {
+                    <#inner_ty as #import::ToPrimitive>::to_u16(&self.0)
+                }
+                #[inline]
+                fn to_u32(&self) -> Option<u32> {
+                    <#inner_ty as #import::ToPrimitive>::to_u32(&self.0)
+                }
+                #[inline]
+                fn to_u128(&self) -> Option<u128> {
+                    <#inner_ty as #import::ToPrimitive>::to_u128(&self.0)
+                }
+                #[inline]
+                fn to_f32(&self) -> Option<f32> {
+                    <#inner_ty as #import::ToPrimitive>::to_f32(&self.0)
+                }
+                #[inline]
+                fn to_f64(&self) -> Option<f64> {
+                    <#inner_ty as #import::ToPrimitive>::to_f64(&self.0)
+                }
+            }
+        }
+    } else {
+        let variants = match ast.data {
+            Data::Enum(ref data_enum) => &data_enum.variants,
+            _ => panic!(
+                "`ToPrimitive` can be applied only to enums and newtypes, {} is neither",
+                name
+            ),
+        };
+
+        let variants: Vec<_> = variants
+            .iter()
+            .map(|variant| {
+                let ident = &variant.ident;
+                match variant.fields {
+                    Fields::Unit => (),
+                    _ => {
+                        panic!("`ToPrimitive` can be applied only to unitary enums and newtypes, {}::{} is either struct or tuple", name, ident)
+                    },
+                }
+
+                // NB: We have to check each variant individually, because we'll only have `&self`
+                // for the input.  We can't move from that, and it might not be `Clone` or `Copy`.
+                // (Otherwise we could just do `*self as i64` without a `match` at all.)
+                quote!(#name::#ident => #name::#ident as i64)
+            })
+            .collect();
+
+        let match_expr = if variants.is_empty() {
+            // No variants found, so do not use Some to not to trigger `unreachable_code` lint
+            quote! {
+                match *self {}
+            }
+        } else {
+            quote! {
+                Some(match *self {
+                    #(#variants,)*
+                })
+            }
+        };
+
+        quote! {
+            impl #import::ToPrimitive for #name {
+                #[inline]
+                #[allow(trivial_numeric_casts)]
+                fn to_i64(&self) -> Option<i64> {
+                    #match_expr
+                }
+
+                #[inline]
+                fn to_u64(&self) -> Option<u64> {
+                    self.to_i64().map(|x| x as u64)
+                }
+            }
+        }
+    };
+
+    import.wrap("ToPrimitive", &name, impl_).into()
+}
+
+const NEWTYPE_ONLY: &str = "This trait can only be derived for newtypes";
+
+/// Derives [`num_traits::NumOps`][num_ops] for newtypes.  The inner type must already implement
+/// `NumOps`.
+///
+/// [num_ops]: https://docs.rs/num-traits/0.2/num_traits/trait.NumOps.html
+///
+/// Note that, since `NumOps` is really a trait alias for `Add + Sub + Mul + Div + Rem`, this macro
+/// generates impls for _those_ traits.  Furthermore, in all generated impls, `RHS=Self` and
+/// `Output=Self`.
+#[proc_macro_derive(NumOps)]
+pub fn num_ops(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
+    let impl_ = quote! {
+        impl ::core::ops::Add for #name {
+            type Output = Self;
+            #[inline]
+            fn add(self, other: Self) -> Self {
+                #name(<#inner_ty as ::core::ops::Add>::add(self.0, other.0))
+            }
+        }
+        impl ::core::ops::Sub for #name {
+            type Output = Self;
+            #[inline]
+            fn sub(self, other: Self) -> Self {
+                #name(<#inner_ty as ::core::ops::Sub>::sub(self.0, other.0))
+            }
+        }
+        impl ::core::ops::Mul for #name {
+            type Output = Self;
+            #[inline]
+            fn mul(self, other: Self) -> Self {
+                #name(<#inner_ty as ::core::ops::Mul>::mul(self.0, other.0))
+            }
+        }
+        impl ::core::ops::Div for #name {
+            type Output = Self;
+            #[inline]
+            fn div(self, other: Self) -> Self {
+                #name(<#inner_ty as ::core::ops::Div>::div(self.0, other.0))
+            }
+        }
+        impl ::core::ops::Rem for #name {
+            type Output = Self;
+            #[inline]
+            fn rem(self, other: Self) -> Self {
+                #name(<#inner_ty as ::core::ops::Rem>::rem(self.0, other.0))
+            }
+        }
+    };
+    impl_.into()
+}
+
+/// Derives [`num_traits::NumCast`][num_cast] for newtypes.  The inner type must already implement
+/// `NumCast`.
+///
+/// [num_cast]: https://docs.rs/num-traits/0.2/num_traits/cast/trait.NumCast.html
+#[proc_macro_derive(NumCast, attributes(num_traits))]
+pub fn num_cast(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = quote! {
+        impl #import::NumCast for #name {
+            #[inline]
+            fn from<T: #import::ToPrimitive>(n: T) -> Option<Self> {
+                <#inner_ty as #import::NumCast>::from(n).map(#name)
+            }
+        }
+    };
+
+    import.wrap("NumCast", &name, impl_).into()
+}
+
+/// Derives [`num_traits::Zero`][zero] for newtypes.  The inner type must already implement `Zero`.
+///
+/// [zero]: https://docs.rs/num-traits/0.2/num_traits/identities/trait.Zero.html
+#[proc_macro_derive(Zero, attributes(num_traits))]
+pub fn zero(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = quote! {
+        impl #import::Zero for #name {
+            #[inline]
+            fn zero() -> Self {
+                #name(<#inner_ty as #import::Zero>::zero())
+            }
+            #[inline]
+            fn is_zero(&self) -> bool {
+                <#inner_ty as #import::Zero>::is_zero(&self.0)
+            }
+        }
+    };
+
+    import.wrap("Zero", &name, impl_).into()
+}
+
+/// Derives [`num_traits::One`][one] for newtypes.  The inner type must already implement `One`.
+///
+/// [one]: https://docs.rs/num-traits/0.2/num_traits/identities/trait.One.html
+#[proc_macro_derive(One, attributes(num_traits))]
+pub fn one(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = quote! {
+        impl #import::One for #name {
+            #[inline]
+            fn one() -> Self {
+                #name(<#inner_ty as #import::One>::one())
+            }
+            #[inline]
+            fn is_one(&self) -> bool {
+                <#inner_ty as #import::One>::is_one(&self.0)
+            }
+        }
+    };
+
+    import.wrap("One", &name, impl_).into()
+}
+
+/// Derives [`num_traits::Num`][num] for newtypes.  The inner type must already implement `Num`.
+///
+/// [num]: https://docs.rs/num-traits/0.2/num_traits/trait.Num.html
+#[proc_macro_derive(Num, attributes(num_traits))]
+pub fn num(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = quote! {
+        impl #import::Num for #name {
+            type FromStrRadixErr = <#inner_ty as #import::Num>::FromStrRadixErr;
+            #[inline]
+            fn from_str_radix(s: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+                <#inner_ty as #import::Num>::from_str_radix(s, radix).map(#name)
+            }
+        }
+    };
+
+    import.wrap("Num", &name, impl_).into()
+}
+
+/// Derives [`num_traits::Float`][float] for newtypes.  The inner type must already implement
+/// `Float`.
+///
+/// [float]: https://docs.rs/num-traits/0.2/num_traits/float/trait.Float.html
+#[proc_macro_derive(Float, attributes(num_traits))]
+pub fn float(input: TokenStream) -> TokenStream {
+    let ast = parse!(input as syn::DeriveInput);
+    let name = &ast.ident;
+    let inner_ty = newtype_inner(&ast.data).expect(NEWTYPE_ONLY);
+
+    let import = NumTraits::new(&ast);
+
+    let impl_ = quote! {
+        impl #import::Float for #name {
+            #[inline]
+            fn nan() -> Self {
+                #name(<#inner_ty as #import::Float>::nan())
+            }
+            #[inline]
+            fn infinity() -> Self {
+                #name(<#inner_ty as #import::Float>::infinity())
+            }
+            #[inline]
+            fn neg_infinity() -> Self {
+                #name(<#inner_ty as #import::Float>::neg_infinity())
+            }
+            #[inline]
+            fn neg_zero() -> Self {
+                #name(<#inner_ty as #import::Float>::neg_zero())
+            }
+            #[inline]
+            fn min_value() -> Self {
+                #name(<#inner_ty as #import::Float>::min_value())
+            }
+            #[inline]
+            fn min_positive_value() -> Self {
+                #name(<#inner_ty as #import::Float>::min_positive_value())
+            }
+            #[inline]
+            fn max_value() -> Self {
+                #name(<#inner_ty as #import::Float>::max_value())
+            }
+            #[inline]
+            fn is_nan(self) -> bool {
+                <#inner_ty as #import::Float>::is_nan(self.0)
+            }
+            #[inline]
+            fn is_infinite(self) -> bool {
+                <#inner_ty as #import::Float>::is_infinite(self.0)
+            }
+            #[inline]
+            fn is_finite(self) -> bool {
+                <#inner_ty as #import::Float>::is_finite(self.0)
+            }
+            #[inline]
+            fn is_normal(self) -> bool {
+                <#inner_ty as #import::Float>::is_normal(self.0)
+            }
+            #[inline]
+            fn classify(self) -> ::std::num::FpCategory {
+                <#inner_ty as #import::Float>::classify(self.0)
+            }
+            #[inline]
+            fn floor(self) -> Self {
+                #name(<#inner_ty as #import::Float>::floor(self.0))
+            }
+            #[inline]
+            fn ceil(self) -> Self {
+                #name(<#inner_ty as #import::Float>::ceil(self.0))
+            }
+            #[inline]
+            fn round(self) -> Self {
+                #name(<#inner_ty as #import::Float>::round(self.0))
+            }
+            #[inline]
+            fn trunc(self) -> Self {
+                #name(<#inner_ty as #import::Float>::trunc(self.0))
+            }
+            #[inline]
+            fn fract(self) -> Self {
+                #name(<#inner_ty as #import::Float>::fract(self.0))
+            }
+            #[inline]
+            fn abs(self) -> Self {
+                #name(<#inner_ty as #import::Float>::abs(self.0))
+            }
+            #[inline]
+            fn signum(self) -> Self {
+                #name(<#inner_ty as #import::Float>::signum(self.0))
+            }
+            #[inline]
+            fn is_sign_positive(self) -> bool {
+                <#inner_ty as #import::Float>::is_sign_positive(self.0)
+            }
+            #[inline]
+            fn is_sign_negative(self) -> bool {
+                <#inner_ty as #import::Float>::is_sign_negative(self.0)
+            }
+            #[inline]
+            fn mul_add(self, a: Self, b: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::mul_add(self.0, a.0, b.0))
+            }
+            #[inline]
+            fn recip(self) -> Self {
+                #name(<#inner_ty as #import::Float>::recip(self.0))
+            }
+            #[inline]
+            fn powi(self, n: i32) -> Self {
+                #name(<#inner_ty as #import::Float>::powi(self.0, n))
+            }
+            #[inline]
+            fn powf(self, n: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::powf(self.0, n.0))
+            }
+            #[inline]
+            fn sqrt(self) -> Self {
+                #name(<#inner_ty as #import::Float>::sqrt(self.0))
+            }
+            #[inline]
+            fn exp(self) -> Self {
+                #name(<#inner_ty as #import::Float>::exp(self.0))
+            }
+            #[inline]
+            fn exp2(self) -> Self {
+                #name(<#inner_ty as #import::Float>::exp2(self.0))
+            }
+            #[inline]
+            fn ln(self) -> Self {
+                #name(<#inner_ty as #import::Float>::ln(self.0))
+            }
+            #[inline]
+            fn log(self, base: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::log(self.0, base.0))
+            }
+            #[inline]
+            fn log2(self) -> Self {
+                #name(<#inner_ty as #import::Float>::log2(self.0))
+            }
+            #[inline]
+            fn log10(self) -> Self {
+                #name(<#inner_ty as #import::Float>::log10(self.0))
+            }
+            #[inline]
+            fn max(self, other: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::max(self.0, other.0))
+            }
+            #[inline]
+            fn min(self, other: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::min(self.0, other.0))
+            }
+            #[inline]
+            fn abs_sub(self, other: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::abs_sub(self.0, other.0))
+            }
+            #[inline]
+            fn cbrt(self) -> Self {
+                #name(<#inner_ty as #import::Float>::cbrt(self.0))
+            }
+            #[inline]
+            fn hypot(self, other: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::hypot(self.0, other.0))
+            }
+            #[inline]
+            fn sin(self) -> Self {
+                #name(<#inner_ty as #import::Float>::sin(self.0))
+            }
+            #[inline]
+            fn cos(self) -> Self {
+                #name(<#inner_ty as #import::Float>::cos(self.0))
+            }
+            #[inline]
+            fn tan(self) -> Self {
+                #name(<#inner_ty as #import::Float>::tan(self.0))
+            }
+            #[inline]
+            fn asin(self) -> Self {
+                #name(<#inner_ty as #import::Float>::asin(self.0))
+            }
+            #[inline]
+            fn acos(self) -> Self {
+                #name(<#inner_ty as #import::Float>::acos(self.0))
+            }
+            #[inline]
+            fn atan(self) -> Self {
+                #name(<#inner_ty as #import::Float>::atan(self.0))
+            }
+            #[inline]
+            fn atan2(self, other: Self) -> Self {
+                #name(<#inner_ty as #import::Float>::atan2(self.0, other.0))
+            }
+            #[inline]
+            fn sin_cos(self) -> (Self, Self) {
+                let (x, y) = <#inner_ty as #import::Float>::sin_cos(self.0);
+                (#name(x), #name(y))
+            }
+            #[inline]
+            fn exp_m1(self) -> Self {
+                #name(<#inner_ty as #import::Float>::exp_m1(self.0))
+            }
+            #[inline]
+            fn ln_1p(self) -> Self {
+                #name(<#inner_ty as #import::Float>::ln_1p(self.0))
+            }
+            #[inline]
+            fn sinh(self) -> Self {
+                #name(<#inner_ty as #import::Float>::sinh(self.0))
+            }
+            #[inline]
+            fn cosh(self) -> Self {
+                #name(<#inner_ty as #import::Float>::cosh(self.0))
+            }
+            #[inline]
+            fn tanh(self) -> Self {
+                #name(<#inner_ty as #import::Float>::tanh(self.0))
+            }
+            #[inline]
+            fn asinh(self) -> Self {
+                #name(<#inner_ty as #import::Float>::asinh(self.0))
+            }
+            #[inline]
+            fn acosh(self) -> Self {
+                #name(<#inner_ty as #import::Float>::acosh(self.0))
+            }
+            #[inline]
+            fn atanh(self) -> Self {
+                #name(<#inner_ty as #import::Float>::atanh(self.0))
+            }
+            #[inline]
+            fn integer_decode(self) -> (u64, i16, i8) {
+                <#inner_ty as #import::Float>::integer_decode(self.0)
+            }
+            #[inline]
+            fn epsilon() -> Self {
+                #name(<#inner_ty as #import::Float>::epsilon())
+            }
+            #[inline]
+            fn to_degrees(self) -> Self {
+                #name(<#inner_ty as #import::Float>::to_degrees(self.0))
+            }
+            #[inline]
+            fn to_radians(self) -> Self {
+                #name(<#inner_ty as #import::Float>::to_radians(self.0))
+            }
+        }
+    };
+
+    import.wrap("Float", &name, impl_).into()
+}
+
+mod test;
diff --git a/third_party/rust/num-derive/src/test.rs b/third_party/rust/num-derive/src/test.rs
new file mode 100644
index 0000000000..c4cd7fe528
--- /dev/null
+++ b/third_party/rust/num-derive/src/test.rs
@@ -0,0 +1,31 @@
+//! This module uses doc-tests on modules for `compile_fail`
+
+// We need "syn/full" to parse macros.
+// Use `--nocapture` to check the quality of the error message.
+#[cfg(not(feature = "full-syntax"))]
+/// ```compile_fail
+/// macro_rules! get_an_isize {
+///     () => (0_isize)
+/// }
+///
+/// #[derive(num_derive::FromPrimitive)]
+/// pub enum CLikeEnum {
+///     VarA = get_an_isize!(), // error without "syn/full"
+///     VarB = 2,
+/// }
+/// ```
+mod issue16 {}
+
+#[cfg(feature = "full-syntax")]
+/// ```
+/// macro_rules! get_an_isize {
+///     () => (0_isize)
+/// }
+///
+/// #[derive(num_derive::FromPrimitive)]
+/// pub enum CLikeEnum {
+///     VarA = get_an_isize!(), // ok with "syn/full"
+///     VarB = 2,
+/// }
+/// ```
+mod issue16 {}