Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/utils/gen_trait_fn_body.rs')
| -rw-r--r-- | crates/ide-assists/src/utils/gen_trait_fn_body.rs | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/crates/ide-assists/src/utils/gen_trait_fn_body.rs b/crates/ide-assists/src/utils/gen_trait_fn_body.rs index 287001af84..f32e5ce97d 100644 --- a/crates/ide-assists/src/utils/gen_trait_fn_body.rs +++ b/crates/ide-assists/src/utils/gen_trait_fn_body.rs @@ -439,8 +439,10 @@ fn gen_partial_eq(adt: &ast::Adt, func: &ast::Fn) -> Option<()> { let eq_check = make::expr_bin_op(lhs, BinaryOp::CmpOp(CmpOp::Eq { negated: false }), rhs); + let mut n_cases = 0; let mut arms = vec![]; for variant in enum_.variant_list()?.variants() { + n_cases += 1; match variant.field_list() { // => (Self::Bar { bin: l_bin }, Self::Bar { bin: r_bin }) => l_bin == r_bin, Some(ast::FieldList::RecordFieldList(list)) => { @@ -514,8 +516,19 @@ fn gen_partial_eq(adt: &ast::Adt, func: &ast::Fn) -> Option<()> { let expr = match arms.len() { 0 => eq_check, - _ => { - arms.push(make::match_arm(Some(make::wildcard_pat().into()), None, eq_check)); + arms_len => { + // Generate the fallback arm when this enum has >1 variants. + // The fallback arm will be `_ => false,` if we've already gone through every case where the variants of self and other match, + // and `_ => std::mem::discriminant(self) == std::mem::discriminant(other),` otherwise. + if n_cases > 1 { + let lhs = make::wildcard_pat().into(); + let rhs = if arms_len == n_cases { + make::expr_literal("false").into() + } else { + eq_check + }; + arms.push(make::match_arm(Some(lhs), None, rhs)); + } let match_target = make::expr_tuple(vec![lhs_name, rhs_name]); let list = make::match_arm_list(arms).indent(ast::edit::IndentLevel(1)); |