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use rustc::lint::*;
use rustc::hir::*;
use utils::{is_automatically_derived, span_lint};
declare_clippy_lint! {
pub PARTIALEQ_NE_IMPL,
complexity,
"re-implementing `PartialEq::ne`"
}
#[derive(Clone, Copy)]
pub struct Pass;
impl LintPass for Pass {
fn get_lints(&self) -> LintArray {
lint_array!(PARTIALEQ_NE_IMPL)
}
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
fn check_item(&mut self, cx: &LateContext<'a, 'tcx>, item: &'tcx Item) {
if_chain! {
if let ItemImpl(_, _, _, _, Some(ref trait_ref), _, ref impl_items) = item.node;
if !is_automatically_derived(&*item.attrs);
if let Some(eq_trait) = cx.tcx.lang_items().eq_trait();
if trait_ref.path.def.def_id() == eq_trait;
then {
for impl_item in impl_items {
if impl_item.name == "ne" {
span_lint(cx,
PARTIALEQ_NE_IMPL,
impl_item.span,
"re-implementing `PartialEq::ne` is unnecessary")
}
}
}
};
}
}