clippy_lints/src/matches/rest_pat_in_fully_bound_struct.rs

   1 use clippy_utils::diagnostics::span_lint_and_help;
   2 use rustc_hir::{Pat, PatKind, QPath};
   3 use rustc_lint::LateContext;
   4 use rustc_middle::ty;
   5
   6 use super::REST_PAT_IN_FULLY_BOUND_STRUCTS;
   7
   8 pub(crate) fn check(cx: &LateContext<'_>, pat: &Pat<'_>) {
   9     if_chain! {
  10         if !pat.span.from_expansion();
  11         if let PatKind::Struct(QPath::Resolved(_, path), fields, true) = pat.kind;
  12         if let Some(def_id) = path.res.opt_def_id();
  13         let ty = cx.tcx.type_of(def_id);
  14         if let ty::Adt(def, _) = ty.kind();
  15         if def.is_struct() || def.is_union();
  16         if fields.len() == def.non_enum_variant().fields.len();
  17
  18         then {
  19             span_lint_and_help(
  20                 cx,
  21                 REST_PAT_IN_FULLY_BOUND_STRUCTS,
  22                 pat.span,
  23                 "unnecessary use of `..` pattern in struct binding. All fields were already bound",
  24                 None,
  25                 "consider removing `..` from this binding",
  26             );
  27         }
  28     }
  29 }