use proc_macro2::{Ident, Span, TokenStream};
use quote::{quote, ToTokens};
use syn::punctuated::Punctuated;
use syn::{Token, TypeParamBound};
pub type Supertraits = Punctuated<TypeParamBound, Token![+]>;
pub enum InferredBound {
Send,
Sync,
}
pub fn has_bound(supertraits: &Supertraits, bound: &InferredBound) -> bool {
for supertrait in supertraits {
if let TypeParamBound::Trait(supertrait) = supertrait {
if supertrait.path.is_ident(bound)
|| supertrait.path.segments.len() == 3
&& (supertrait.path.segments[0].ident == "std"
|| supertrait.path.segments[0].ident == "core")
&& supertrait.path.segments[1].ident == "marker"
&& supertrait.path.segments[2].ident == *bound
{
return true;
}
}
}
false
}
impl InferredBound {
fn as_str(&self) -> &str {
match self {
InferredBound::Send => "Send",
InferredBound::Sync => "Sync",
}
}
}
impl ToTokens for InferredBound {
fn to_tokens(&self, tokens: &mut TokenStream) {
let ident = Ident::new(self.as_str(), Span::call_site());
quote!(::core::marker::#ident).to_tokens(tokens);
}
}
impl PartialEq<InferredBound> for Ident {
fn eq(&self, bound: &InferredBound) -> bool {
self == bound.as_str()
}
}