1 files changed, 119 insertions, 0 deletions
diff --git a/vendor/clap_derive-3.2.18/src/utils/ty.rs b/vendor/clap_derive-3.2.18/src/utils/ty.rs
new file mode 100644
index 000000000..0bcb59f27
--- /dev/null
+++ b/vendor/clap_derive-3.2.18/src/utils/ty.rs
@@ -0,0 +1,119 @@
+//! Special types handling
+
+use super::spanned::Sp;
+
+use syn::{
+    spanned::Spanned, GenericArgument, Path, PathArguments, PathArguments::AngleBracketed,
+    PathSegment, Type, TypePath,
+};
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum Ty {
+    Vec,
+    Option,
+    OptionOption,
+    OptionVec,
+    Other,
+}
+
+impl Ty {
+    pub fn from_syn_ty(ty: &syn::Type) -> Sp<Self> {
+        use self::Ty::*;
+        let t = |kind| Sp::new(kind, ty.span());
+
+        if is_generic_ty(ty, "Vec") {
+            t(Vec)
+        } else if let Some(subty) = subty_if_name(ty, "Option") {
+            if is_generic_ty(subty, "Option") {
+                t(OptionOption)
+            } else if is_generic_ty(subty, "Vec") {
+                t(OptionVec)
+            } else {
+                t(Option)
+            }
+        } else {
+            t(Other)
+        }
+    }
+}
+
+pub fn inner_type(field_ty: &syn::Type) -> &syn::Type {
+    let ty = Ty::from_syn_ty(field_ty);
+    match *ty {
+        Ty::Vec | Ty::Option => sub_type(field_ty).unwrap_or(field_ty),
+        Ty::OptionOption | Ty::OptionVec => {
+            sub_type(field_ty).and_then(sub_type).unwrap_or(field_ty)
+        }
+        _ => field_ty,
+    }
+}
+
+pub fn sub_type(ty: &syn::Type) -> Option<&syn::Type> {
+    subty_if(ty, |_| true)
+}
+
+fn only_last_segment(mut ty: &syn::Type) -> Option<&PathSegment> {
+    while let syn::Type::Group(syn::TypeGroup { elem, .. }) = ty {
+        ty = elem;
+    }
+    match ty {
+        Type::Path(TypePath {
+            qself: None,
+            path:
+                Path {
+                    leading_colon: None,
+                    segments,
+                },
+        }) => only_one(segments.iter()),
+
+        _ => None,
+    }
+}
+
+fn subty_if<F>(ty: &syn::Type, f: F) -> Option<&syn::Type>
+where
+    F: FnOnce(&PathSegment) -> bool,
+{
+    only_last_segment(ty)
+        .filter(|segment| f(segment))
+        .and_then(|segment| {
+            if let AngleBracketed(args) = &segment.arguments {
+                only_one(args.args.iter()).and_then(|genneric| {
+                    if let GenericArgument::Type(ty) = genneric {
+                        Some(ty)
+                    } else {
+                        None
+                    }
+                })
+            } else {
+                None
+            }
+        })
+}
+
+pub fn subty_if_name<'a>(ty: &'a syn::Type, name: &str) -> Option<&'a syn::Type> {
+    subty_if(ty, |seg| seg.ident == name)
+}
+
+pub fn is_simple_ty(ty: &syn::Type, name: &str) -> bool {
+    only_last_segment(ty)
+        .map(|segment| {
+            if let PathArguments::None = segment.arguments {
+                segment.ident == name
+            } else {
+                false
+            }
+        })
+        .unwrap_or(false)
+}
+
+fn is_generic_ty(ty: &syn::Type, name: &str) -> bool {
+    subty_if_name(ty, name).is_some()
+}
+
+fn only_one<I, T>(mut iter: I) -> Option<T>
+where
+    I: Iterator<Item = T>,
+{
+    iter.next().filter(|_| iter.next().is_none())
+}