1 files changed, 101 insertions, 0 deletions
diff --git a/vendor/derive_more/src/unwrap.rs b/vendor/derive_more/src/unwrap.rs
new file mode 100644
index 000000000..e2243d3a2
--- /dev/null
+++ b/vendor/derive_more/src/unwrap.rs
@@ -0,0 +1,101 @@
+use crate::utils::{AttrParams, DeriveType, State};
+use convert_case::{Case, Casing};
+use proc_macro2::TokenStream;
+use quote::{format_ident, quote};
+use syn::{DeriveInput, Fields, Ident, Result};
+
+pub fn expand(input: &DeriveInput, trait_name: &'static str) -> Result<TokenStream> {
+    let state = State::with_attr_params(
+        input,
+        trait_name,
+        quote!(),
+        String::from("unwrap"),
+        AttrParams {
+            enum_: vec!["ignore"],
+            variant: vec!["ignore"],
+            struct_: vec!["ignore"],
+            field: vec!["ignore"],
+        },
+    )?;
+    assert!(
+        state.derive_type == DeriveType::Enum,
+        "Unwrap can only be derived for enums"
+    );
+
+    let enum_name = &input.ident;
+    let (imp_generics, type_generics, where_clause) = input.generics.split_for_impl();
+
+    let mut funcs = vec![];
+    for variant_state in state.enabled_variant_data().variant_states {
+        let variant = variant_state.variant.unwrap();
+        let fn_name = Ident::new(
+            &format_ident!("unwrap_{}", variant.ident)
+                .to_string()
+                .to_case(Case::Snake),
+            variant.ident.span(),
+        );
+        let variant_ident = &variant.ident;
+
+        let (data_pattern, ret_value, ret_type) = match variant.fields {
+            Fields::Named(_) => panic!("cannot unwrap anonymous records"),
+            Fields::Unnamed(ref fields) => {
+                let data_pattern =
+                    (0..fields.unnamed.len()).fold(vec![], |mut a, n| {
+                        a.push(format_ident!("field_{}", n));
+                        a
+                    });
+                let ret_type = &fields.unnamed;
+                (
+                    quote! { (#(#data_pattern),*) },
+                    quote! { (#(#data_pattern),*) },
+                    quote! { (#ret_type) },
+                )
+            }
+            Fields::Unit => (quote! {}, quote! { () }, quote! { () }),
+        };
+
+        let other_arms = state.variant_states.iter().map(|variant| {
+            variant.variant.unwrap()
+        }).filter(|variant| {
+            &variant.ident != variant_ident
+        }).map(|variant| {
+            let data_pattern = match variant.fields {
+                Fields::Named(_) => quote! { {..} },
+                Fields::Unnamed(_) => quote! { (..) },
+                Fields::Unit => quote! {},
+            };
+            let variant_ident = &variant.ident;
+            quote! { #enum_name :: #variant_ident #data_pattern =>
+                      panic!(concat!("called `", stringify!(#enum_name), "::", stringify!(#fn_name),
+                                     "()` on a `", stringify!(#variant_ident), "` value"))
+            }
+        });
+
+        // The `track-caller` feature is set by our build script based
+        // on rustc version detection, as `#[track_caller]` was
+        // stabilized in a later version (1.46) of Rust than our MSRV (1.36).
+        let track_caller = if cfg!(feature = "track-caller") {
+            quote! { #[track_caller] }
+        } else {
+            quote! {}
+        };
+        let func = quote! {
+            #track_caller
+            pub fn #fn_name(self) -> #ret_type {
+                match self {
+                    #enum_name ::#variant_ident #data_pattern => #ret_value,
+                    #(#other_arms),*
+                }
+            }
+        };
+        funcs.push(func);
+    }
+
+    let imp = quote! {
+        impl #imp_generics #enum_name #type_generics #where_clause{
+            #(#funcs)*
+        }
+    };
+
+    Ok(imp)
+}