diff --git a/CHANGELOG.md b/CHANGELOG.md index 50fe7612909b..f662de122f99 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1754,6 +1754,7 @@ Released 2018-09-13 [`unnecessary_cast`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_cast [`unnecessary_filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_filter_map [`unnecessary_fold`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold +[`unnecessary_lazy_evaluations`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations [`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed [`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation [`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 986e9d9bee4d..17501e8e6da4 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -685,6 +685,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: &methods::UNINIT_ASSUMED_INIT, &methods::UNNECESSARY_FILTER_MAP, &methods::UNNECESSARY_FOLD, + &methods::UNNECESSARY_LAZY_EVALUATIONS, &methods::UNWRAP_USED, &methods::USELESS_ASREF, &methods::WRONG_PUB_SELF_CONVENTION, @@ -1360,6 +1361,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&methods::UNINIT_ASSUMED_INIT), LintId::of(&methods::UNNECESSARY_FILTER_MAP), LintId::of(&methods::UNNECESSARY_FOLD), + LintId::of(&methods::UNNECESSARY_LAZY_EVALUATIONS), LintId::of(&methods::USELESS_ASREF), LintId::of(&methods::WRONG_SELF_CONVENTION), LintId::of(&methods::ZST_OFFSET), @@ -1540,6 +1542,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: LintId::of(&methods::SINGLE_CHAR_PUSH_STR), LintId::of(&methods::STRING_EXTEND_CHARS), LintId::of(&methods::UNNECESSARY_FOLD), + LintId::of(&methods::UNNECESSARY_LAZY_EVALUATIONS), LintId::of(&methods::WRONG_SELF_CONVENTION), LintId::of(&misc::TOPLEVEL_REF_ARG), LintId::of(&misc::ZERO_PTR), diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 2330978e67f1..0f50a4c813ad 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -3,6 +3,7 @@ mod inefficient_to_string; mod manual_saturating_arithmetic; mod option_map_unwrap_or; mod unnecessary_filter_map; +mod unnecessary_lazy_eval; use std::borrow::Cow; use std::fmt; @@ -1329,6 +1330,42 @@ declare_clippy_lint! { "`push_str()` used with a single-character string literal as parameter" } +declare_clippy_lint! { + /// **What it does:** As the counterpart to `or_fun_call`, this lint looks for unnecessary + /// lazily evaluated closures on `Option` and `Result`. + /// + /// This lint suggests changing the following functions, when eager evaluation results in + /// simpler code: + /// - `unwrap_or_else` to `unwrap_or` + /// - `and_then` to `and` + /// - `or_else` to `or` + /// - `get_or_insert_with` to `get_or_insert` + /// - `ok_or_else` to `ok_or` + /// + /// **Why is this bad?** Using eager evaluation is shorter and simpler in some cases. + /// + /// **Known problems:** It is possible, but not recommended for `Deref` and `Index` to have + /// side effects. Eagerly evaluating them can change the semantics of the program. + /// + /// **Example:** + /// + /// ```rust + /// // example code where clippy issues a warning + /// let opt: Option = None; + /// + /// opt.unwrap_or_else(|| 42); + /// ``` + /// Use instead: + /// ```rust + /// let opt: Option = None; + /// + /// opt.unwrap_or(42); + /// ``` + pub UNNECESSARY_LAZY_EVALUATIONS, + style, + "using unnecessary lazy evaluation, which can be replaced with simpler eager evaluation" +} + declare_lint_pass!(Methods => [ UNWRAP_USED, EXPECT_USED, @@ -1378,6 +1415,7 @@ declare_lint_pass!(Methods => [ ZST_OFFSET, FILETYPE_IS_FILE, OPTION_AS_REF_DEREF, + UNNECESSARY_LAZY_EVALUATIONS, ]); impl<'tcx> LateLintPass<'tcx> for Methods { @@ -1398,13 +1436,19 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["expect", "ok"] => lint_ok_expect(cx, expr, arg_lists[1]), ["expect", ..] => lint_expect(cx, expr, arg_lists[0]), ["unwrap_or", "map"] => option_map_unwrap_or::lint(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]), - ["unwrap_or_else", "map"] => lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0]), + ["unwrap_or_else", "map"] => { + if !lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0]) { + unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "unwrap_or"); + } + }, ["map_or", ..] => lint_map_or_none(cx, expr, arg_lists[0]), ["and_then", ..] => { + unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], false, "and"); bind_instead_of_map::OptionAndThenSome::lint(cx, expr, arg_lists[0]); bind_instead_of_map::ResultAndThenOk::lint(cx, expr, arg_lists[0]); }, ["or_else", ..] => { + unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], false, "or"); bind_instead_of_map::ResultOrElseErrInfo::lint(cx, expr, arg_lists[0]); }, ["next", "filter"] => lint_filter_next(cx, expr, arg_lists[1]), @@ -1448,6 +1492,9 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["is_file", ..] => lint_filetype_is_file(cx, expr, arg_lists[0]), ["map", "as_ref"] => lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], false), ["map", "as_mut"] => lint_option_as_ref_deref(cx, expr, arg_lists[1], arg_lists[0], true), + ["unwrap_or_else", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "unwrap_or"), + ["get_or_insert_with", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "get_or_insert"), + ["ok_or_else", ..] => unnecessary_lazy_eval::lint(cx, expr, arg_lists[0], true, "ok_or"), _ => {}, } @@ -2664,12 +2711,13 @@ fn lint_map_flatten<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map } /// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s +/// Return true if lint triggered fn lint_map_unwrap_or_else<'tcx>( cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>, map_args: &'tcx [hir::Expr<'_>], unwrap_args: &'tcx [hir::Expr<'_>], -) { +) -> bool { // lint if the caller of `map()` is an `Option` let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym!(option_type)); let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym!(result_type)); @@ -2681,10 +2729,10 @@ fn lint_map_unwrap_or_else<'tcx>( let unwrap_mutated_vars = mutated_variables(&unwrap_args[1], cx); if let (Some(map_mutated_vars), Some(unwrap_mutated_vars)) = (map_mutated_vars, unwrap_mutated_vars) { if map_mutated_vars.intersection(&unwrap_mutated_vars).next().is_some() { - return; + return false; } } else { - return; + return false; } // lint message @@ -2714,10 +2762,14 @@ fn lint_map_unwrap_or_else<'tcx>( map_snippet, unwrap_snippet, ), ); + return true; } else if same_span && multiline { span_lint(cx, MAP_UNWRAP_OR, expr.span, msg); - }; + return true; + } } + + false } /// lint use of `_.map_or(None, _)` for `Option`s and `Result`s diff --git a/clippy_lints/src/methods/unnecessary_lazy_eval.rs b/clippy_lints/src/methods/unnecessary_lazy_eval.rs new file mode 100644 index 000000000000..31517659c34d --- /dev/null +++ b/clippy_lints/src/methods/unnecessary_lazy_eval.rs @@ -0,0 +1,111 @@ +use crate::utils::{is_type_diagnostic_item, match_qpath, snippet, span_lint_and_sugg}; +use if_chain::if_chain; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; + +use super::UNNECESSARY_LAZY_EVALUATIONS; + +// Return true if the expression is an accessor of any of the arguments +fn expr_uses_argument(expr: &hir::Expr<'_>, params: &[hir::Param<'_>]) -> bool { + params.iter().any(|arg| { + if_chain! { + if let hir::PatKind::Binding(_, _, ident, _) = arg.pat.kind; + if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = expr.kind; + if let [p, ..] = path.segments; + then { + ident.name == p.ident.name + } else { + false + } + } + }) +} + +fn match_any_qpath(path: &hir::QPath<'_>, paths: &[&[&str]]) -> bool { + paths.iter().any(|candidate| match_qpath(path, candidate)) +} + +fn can_simplify(expr: &hir::Expr<'_>, params: &[hir::Param<'_>], variant_calls: bool) -> bool { + match expr.kind { + // Closures returning literals can be unconditionally simplified + hir::ExprKind::Lit(_) => true, + + hir::ExprKind::Index(ref object, ref index) => { + // arguments are not being indexed into + if expr_uses_argument(object, params) { + false + } else { + // arguments are not used as index + !expr_uses_argument(index, params) + } + }, + + // Reading fields can be simplified if the object is not an argument of the closure + hir::ExprKind::Field(ref object, _) => !expr_uses_argument(object, params), + + // Paths can be simplified if the root is not the argument, this also covers None + hir::ExprKind::Path(_) => !expr_uses_argument(expr, params), + + // Calls to Some, Ok, Err can be considered literals if they don't derive an argument + hir::ExprKind::Call(ref func, ref args) => if_chain! { + if variant_calls; // Disable lint when rules conflict with bind_instead_of_map + if let hir::ExprKind::Path(ref path) = func.kind; + if match_any_qpath(path, &[&["Some"], &["Ok"], &["Err"]]); + then { + // Recursively check all arguments + args.iter().all(|arg| can_simplify(arg, params, variant_calls)) + } else { + false + } + }, + + // For anything more complex than the above, a closure is probably the right solution, + // or the case is handled by an other lint + _ => false, + } +} + +/// lint use of `_else(simple closure)` for `Option`s and `Result`s that can be +/// replaced with `(return value of simple closure)` +pub(super) fn lint<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + args: &'tcx [hir::Expr<'_>], + allow_variant_calls: bool, + simplify_using: &str, +) { + let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&args[0]), sym!(option_type)); + let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&args[0]), sym!(result_type)); + + if is_option || is_result { + if let hir::ExprKind::Closure(_, _, eid, _, _) = args[1].kind { + let body = cx.tcx.hir().body(eid); + let ex = &body.value; + let params = &body.params; + + if can_simplify(ex, params, allow_variant_calls) { + let msg = if is_option { + "unnecessary closure used to substitute value for `Option::None`" + } else { + "unnecessary closure used to substitute value for `Result::Err`" + }; + + span_lint_and_sugg( + cx, + UNNECESSARY_LAZY_EVALUATIONS, + expr.span, + msg, + &format!("Use `{}` instead", simplify_using), + format!( + "{0}.{1}({2})", + snippet(cx, args[0].span, ".."), + simplify_using, + snippet(cx, ex.span, ".."), + ), + Applicability::MachineApplicable, + ); + } + } + } +} diff --git a/src/lintlist/mod.rs b/src/lintlist/mod.rs index 233f95deeddc..3229c8da5077 100644 --- a/src/lintlist/mod.rs +++ b/src/lintlist/mod.rs @@ -2383,6 +2383,13 @@ pub static ref ALL_LINTS: Vec = vec![ deprecation: None, module: "methods", }, + Lint { + name: "unnecessary_lazy_evaluations", + group: "style", + desc: "using unnecessary lazy evaluation, which can be replaced with simpler eager evaluation", + deprecation: None, + module: "methods", + }, Lint { name: "unnecessary_mut_passed", group: "style", diff --git a/tests/ui/unnecessary_lazy_eval.fixed b/tests/ui/unnecessary_lazy_eval.fixed new file mode 100644 index 000000000000..fa66e68794e4 --- /dev/null +++ b/tests/ui/unnecessary_lazy_eval.fixed @@ -0,0 +1,117 @@ +// run-rustfix +#![warn(clippy::unnecessary_lazy_evaluations)] +#![allow(clippy::redundant_closure)] +#![allow(clippy::bind_instead_of_map)] + +struct Deep(Option); + +#[derive(Copy, Clone)] +struct SomeStruct { + some_field: usize, +} + +impl SomeStruct { + fn return_some_field(&self) -> usize { + self.some_field + } +} + +fn some_call() -> T { + T::default() +} + +fn main() { + let astronomers_pi = 10; + let ext_arr: [usize; 1] = [2]; + let ext_str = SomeStruct { some_field: 10 }; + + let mut opt = Some(42); + let ext_opt = Some(42); + let nested_opt = Some(Some(42)); + let nested_tuple_opt = Some(Some((42, 43))); + + // Should lint - Option + let _ = opt.unwrap_or(2); + let _ = opt.unwrap_or(astronomers_pi); + let _ = opt.unwrap_or(ext_str.some_field); + let _ = opt.unwrap_or(ext_arr[0]); + let _ = opt.and(ext_opt); + let _ = opt.or(ext_opt); + let _ = opt.or(None); + let _ = opt.get_or_insert(2); + let _ = opt.ok_or(2); + let _ = opt.ok_or(ext_arr[0]); + + // Cases when unwrap is not called on a simple variable + let _ = Some(10).unwrap_or(2); + let _ = Some(10).and(ext_opt); + let _: Option = None.or(ext_opt); + let _ = None.get_or_insert(2); + let _: Result = None.ok_or(2); + let _: Option = None.or(None); + + let mut deep = Deep(Some(42)); + let _ = deep.0.unwrap_or(2); + let _ = deep.0.and(ext_opt); + let _ = deep.0.or(None); + let _ = deep.0.get_or_insert(2); + let _ = deep.0.ok_or(2); + + // Should not lint - Option + let _ = opt.unwrap_or_else(|| ext_str.return_some_field()); + let _ = nested_opt.unwrap_or_else(|| Some(some_call())); + let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2))); + let _ = nested_tuple_opt.unwrap_or_else(|| Some((some_call(), some_call()))); + let _ = opt.or_else(some_call); + let _ = opt.or_else(|| some_call()); + let _: Result = opt.ok_or_else(|| some_call()); + let _: Result = opt.ok_or_else(some_call); + let _ = deep.0.get_or_insert_with(|| some_call()); + let _ = deep.0.or_else(some_call); + let _ = deep.0.or_else(|| some_call()); + + // These are handled by bind_instead_of_map + let _ = Some(10).and_then(|idx| Some(ext_arr[idx])); + let _ = Some(10).and_then(|idx| Some(idx)); + let _: Option = None.or_else(|| Some(3)); + let _ = deep.0.or_else(|| Some(3)); + let _ = opt.or_else(|| Some(3)); + + // Should lint - Result + let res: Result = Err(5); + let res2: Result = Err(SomeStruct { some_field: 5 }); + + let _ = res2.unwrap_or(2); + let _ = res2.unwrap_or(astronomers_pi); + let _ = res2.unwrap_or(ext_str.some_field); + + // Should not lint - Result + let _ = res.unwrap_or_else(|err| err); + let _ = res.unwrap_or_else(|err| ext_arr[err]); + let _ = res2.unwrap_or_else(|err| err.some_field); + let _ = res2.unwrap_or_else(|err| err.return_some_field()); + let _ = res2.unwrap_or_else(|_| ext_str.return_some_field()); + + let _: Result = res.and_then(|x| Ok(x)); + let _: Result = res.and_then(|x| Err(x)); + + let _: Result = res.or_else(|err| Ok(err)); + let _: Result = res.or_else(|err| Err(err)); + + // These are handled by bind_instead_of_map + let _: Result = res.and_then(|_| Ok(2)); + let _: Result = res.and_then(|_| Ok(astronomers_pi)); + let _: Result = res.and_then(|_| Ok(ext_str.some_field)); + + let _: Result = res.and_then(|_| Err(2)); + let _: Result = res.and_then(|_| Err(astronomers_pi)); + let _: Result = res.and_then(|_| Err(ext_str.some_field)); + + let _: Result = res.or_else(|_| Ok(2)); + let _: Result = res.or_else(|_| Ok(astronomers_pi)); + let _: Result = res.or_else(|_| Ok(ext_str.some_field)); + + let _: Result = res.or_else(|_| Err(2)); + let _: Result = res.or_else(|_| Err(astronomers_pi)); + let _: Result = res.or_else(|_| Err(ext_str.some_field)); +} diff --git a/tests/ui/unnecessary_lazy_eval.rs b/tests/ui/unnecessary_lazy_eval.rs new file mode 100644 index 000000000000..04f47d1aa297 --- /dev/null +++ b/tests/ui/unnecessary_lazy_eval.rs @@ -0,0 +1,117 @@ +// run-rustfix +#![warn(clippy::unnecessary_lazy_evaluations)] +#![allow(clippy::redundant_closure)] +#![allow(clippy::bind_instead_of_map)] + +struct Deep(Option); + +#[derive(Copy, Clone)] +struct SomeStruct { + some_field: usize, +} + +impl SomeStruct { + fn return_some_field(&self) -> usize { + self.some_field + } +} + +fn some_call() -> T { + T::default() +} + +fn main() { + let astronomers_pi = 10; + let ext_arr: [usize; 1] = [2]; + let ext_str = SomeStruct { some_field: 10 }; + + let mut opt = Some(42); + let ext_opt = Some(42); + let nested_opt = Some(Some(42)); + let nested_tuple_opt = Some(Some((42, 43))); + + // Should lint - Option + let _ = opt.unwrap_or_else(|| 2); + let _ = opt.unwrap_or_else(|| astronomers_pi); + let _ = opt.unwrap_or_else(|| ext_str.some_field); + let _ = opt.unwrap_or_else(|| ext_arr[0]); + let _ = opt.and_then(|_| ext_opt); + let _ = opt.or_else(|| ext_opt); + let _ = opt.or_else(|| None); + let _ = opt.get_or_insert_with(|| 2); + let _ = opt.ok_or_else(|| 2); + let _ = opt.ok_or_else(|| ext_arr[0]); + + // Cases when unwrap is not called on a simple variable + let _ = Some(10).unwrap_or_else(|| 2); + let _ = Some(10).and_then(|_| ext_opt); + let _: Option = None.or_else(|| ext_opt); + let _ = None.get_or_insert_with(|| 2); + let _: Result = None.ok_or_else(|| 2); + let _: Option = None.or_else(|| None); + + let mut deep = Deep(Some(42)); + let _ = deep.0.unwrap_or_else(|| 2); + let _ = deep.0.and_then(|_| ext_opt); + let _ = deep.0.or_else(|| None); + let _ = deep.0.get_or_insert_with(|| 2); + let _ = deep.0.ok_or_else(|| 2); + + // Should not lint - Option + let _ = opt.unwrap_or_else(|| ext_str.return_some_field()); + let _ = nested_opt.unwrap_or_else(|| Some(some_call())); + let _ = nested_tuple_opt.unwrap_or_else(|| Some((1, 2))); + let _ = nested_tuple_opt.unwrap_or_else(|| Some((some_call(), some_call()))); + let _ = opt.or_else(some_call); + let _ = opt.or_else(|| some_call()); + let _: Result = opt.ok_or_else(|| some_call()); + let _: Result = opt.ok_or_else(some_call); + let _ = deep.0.get_or_insert_with(|| some_call()); + let _ = deep.0.or_else(some_call); + let _ = deep.0.or_else(|| some_call()); + + // These are handled by bind_instead_of_map + let _ = Some(10).and_then(|idx| Some(ext_arr[idx])); + let _ = Some(10).and_then(|idx| Some(idx)); + let _: Option = None.or_else(|| Some(3)); + let _ = deep.0.or_else(|| Some(3)); + let _ = opt.or_else(|| Some(3)); + + // Should lint - Result + let res: Result = Err(5); + let res2: Result = Err(SomeStruct { some_field: 5 }); + + let _ = res2.unwrap_or_else(|_| 2); + let _ = res2.unwrap_or_else(|_| astronomers_pi); + let _ = res2.unwrap_or_else(|_| ext_str.some_field); + + // Should not lint - Result + let _ = res.unwrap_or_else(|err| err); + let _ = res.unwrap_or_else(|err| ext_arr[err]); + let _ = res2.unwrap_or_else(|err| err.some_field); + let _ = res2.unwrap_or_else(|err| err.return_some_field()); + let _ = res2.unwrap_or_else(|_| ext_str.return_some_field()); + + let _: Result = res.and_then(|x| Ok(x)); + let _: Result = res.and_then(|x| Err(x)); + + let _: Result = res.or_else(|err| Ok(err)); + let _: Result = res.or_else(|err| Err(err)); + + // These are handled by bind_instead_of_map + let _: Result = res.and_then(|_| Ok(2)); + let _: Result = res.and_then(|_| Ok(astronomers_pi)); + let _: Result = res.and_then(|_| Ok(ext_str.some_field)); + + let _: Result = res.and_then(|_| Err(2)); + let _: Result = res.and_then(|_| Err(astronomers_pi)); + let _: Result = res.and_then(|_| Err(ext_str.some_field)); + + let _: Result = res.or_else(|_| Ok(2)); + let _: Result = res.or_else(|_| Ok(astronomers_pi)); + let _: Result = res.or_else(|_| Ok(ext_str.some_field)); + + let _: Result = res.or_else(|_| Err(2)); + let _: Result = res.or_else(|_| Err(astronomers_pi)); + let _: Result = res.or_else(|_| Err(ext_str.some_field)); +} diff --git a/tests/ui/unnecessary_lazy_eval.stderr b/tests/ui/unnecessary_lazy_eval.stderr new file mode 100644 index 000000000000..5c1b2eb1f14e --- /dev/null +++ b/tests/ui/unnecessary_lazy_eval.stderr @@ -0,0 +1,148 @@ +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:34:13 + | +LL | let _ = opt.unwrap_or_else(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `opt.unwrap_or(2)` + | + = note: `-D clippy::unnecessary-lazy-evaluations` implied by `-D warnings` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:35:13 + | +LL | let _ = opt.unwrap_or_else(|| astronomers_pi); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `opt.unwrap_or(astronomers_pi)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:36:13 + | +LL | let _ = opt.unwrap_or_else(|| ext_str.some_field); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `opt.unwrap_or(ext_str.some_field)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:37:13 + | +LL | let _ = opt.unwrap_or_else(|| ext_arr[0]); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `opt.unwrap_or(ext_arr[0])` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:38:13 + | +LL | let _ = opt.and_then(|_| ext_opt); + | ^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `and` instead: `opt.and(ext_opt)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:39:13 + | +LL | let _ = opt.or_else(|| ext_opt); + | ^^^^^^^^^^^^^^^^^^^^^^^ help: Use `or` instead: `opt.or(ext_opt)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:40:13 + | +LL | let _ = opt.or_else(|| None); + | ^^^^^^^^^^^^^^^^^^^^ help: Use `or` instead: `opt.or(None)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:41:13 + | +LL | let _ = opt.get_or_insert_with(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `get_or_insert` instead: `opt.get_or_insert(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:42:13 + | +LL | let _ = opt.ok_or_else(|| 2); + | ^^^^^^^^^^^^^^^^^^^^ help: Use `ok_or` instead: `opt.ok_or(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:43:13 + | +LL | let _ = opt.ok_or_else(|| ext_arr[0]); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `ok_or` instead: `opt.ok_or(ext_arr[0])` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:46:13 + | +LL | let _ = Some(10).unwrap_or_else(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `Some(10).unwrap_or(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:47:13 + | +LL | let _ = Some(10).and_then(|_| ext_opt); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `and` instead: `Some(10).and(ext_opt)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:48:28 + | +LL | let _: Option = None.or_else(|| ext_opt); + | ^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `or` instead: `None.or(ext_opt)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:49:13 + | +LL | let _ = None.get_or_insert_with(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `get_or_insert` instead: `None.get_or_insert(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:50:35 + | +LL | let _: Result = None.ok_or_else(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^ help: Use `ok_or` instead: `None.ok_or(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:51:28 + | +LL | let _: Option = None.or_else(|| None); + | ^^^^^^^^^^^^^^^^^^^^^ help: Use `or` instead: `None.or(None)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:54:13 + | +LL | let _ = deep.0.unwrap_or_else(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `deep.0.unwrap_or(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:55:13 + | +LL | let _ = deep.0.and_then(|_| ext_opt); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `and` instead: `deep.0.and(ext_opt)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:56:13 + | +LL | let _ = deep.0.or_else(|| None); + | ^^^^^^^^^^^^^^^^^^^^^^^ help: Use `or` instead: `deep.0.or(None)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:57:13 + | +LL | let _ = deep.0.get_or_insert_with(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `get_or_insert` instead: `deep.0.get_or_insert(2)` + +error: unnecessary closure used to substitute value for `Option::None` + --> $DIR/unnecessary_lazy_eval.rs:58:13 + | +LL | let _ = deep.0.ok_or_else(|| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^ help: Use `ok_or` instead: `deep.0.ok_or(2)` + +error: unnecessary closure used to substitute value for `Result::Err` + --> $DIR/unnecessary_lazy_eval.rs:84:13 + | +LL | let _ = res2.unwrap_or_else(|_| 2); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `res2.unwrap_or(2)` + +error: unnecessary closure used to substitute value for `Result::Err` + --> $DIR/unnecessary_lazy_eval.rs:85:13 + | +LL | let _ = res2.unwrap_or_else(|_| astronomers_pi); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `res2.unwrap_or(astronomers_pi)` + +error: unnecessary closure used to substitute value for `Result::Err` + --> $DIR/unnecessary_lazy_eval.rs:86:13 + | +LL | let _ = res2.unwrap_or_else(|_| ext_str.some_field); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: Use `unwrap_or` instead: `res2.unwrap_or(ext_str.some_field)` + +error: aborting due to 24 previous errors +