#![feature(exhaustive_patterns, never_type)] #![allow(dead_code, unreachable_code, unused_variables)] #![allow(clippy::let_and_return)] enum SingleVariantEnum { Variant(i32), } struct TupleStruct(i32); struct NonCopy; struct TupleStructWithNonCopy(NonCopy); enum EmptyEnum {} macro_rules! match_enum { ($param:expr) => { let data = match $param { SingleVariantEnum::Variant(i) => i, }; }; } fn infallible_destructuring_match_enum() { let wrapper = SingleVariantEnum::Variant(0); // This should lint! let SingleVariantEnum::Variant(data) = wrapper; // This shouldn't (inside macro) match_enum!(wrapper); // This shouldn't! let data = match wrapper { SingleVariantEnum::Variant(_) => -1, }; // Neither should this! let data = match wrapper { SingleVariantEnum::Variant(i) => -1, }; let SingleVariantEnum::Variant(data) = wrapper; } macro_rules! match_struct { ($param:expr) => { let data = match $param { TupleStruct(i) => i, }; }; } fn infallible_destructuring_match_struct() { let wrapper = TupleStruct(0); // This should lint! let TupleStruct(data) = wrapper; // This shouldn't (inside macro) match_struct!(wrapper); // This shouldn't! let data = match wrapper { TupleStruct(_) => -1, }; // Neither should this! let data = match wrapper { TupleStruct(i) => -1, }; let TupleStruct(data) = wrapper; } fn infallible_destructuring_match_struct_with_noncopy() { let wrapper = TupleStructWithNonCopy(NonCopy); // This should lint! (keeping `ref` in the suggestion) let TupleStructWithNonCopy(ref data) = wrapper; let TupleStructWithNonCopy(ref data) = wrapper; } macro_rules! match_never_enum { ($param:expr) => { let data = match $param { Ok(i) => i, }; }; } fn never_enum() { let wrapper: Result = Ok(23); // This should lint! let Ok(data) = wrapper; // This shouldn't (inside macro) match_never_enum!(wrapper); // This shouldn't! let data = match wrapper { Ok(_) => -1, }; // Neither should this! let data = match wrapper { Ok(i) => -1, }; let Ok(data) = wrapper; } impl EmptyEnum { fn match_on(&self) -> ! { // The lint shouldn't pick this up, as `let` won't work here! let data = match *self {}; data } } fn main() {}