Auto merge of #6801 - Jarcho:manual_match_fix, r=phansch

Fix `manual_map` false positives

fixes: #6795
fixes: #6797
fixes: #6811
fixes: #6819

changelog: Fix false positives for `manual_map` when `return`, `break`, `continue`, `yield`, `await`, and partially moved values are used.
changelog: Don't expand macros in suggestions  for `manual_map`
This commit is contained in:
bors 2021-03-02 15:36:00 +00:00
commit ece3543c9f
6 changed files with 348 additions and 96 deletions

View file

@ -1543,6 +1543,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&loops::WHILE_LET_ON_ITERATOR),
LintId::of(&main_recursion::MAIN_RECURSION),
LintId::of(&manual_async_fn::MANUAL_ASYNC_FN),
LintId::of(&manual_map::MANUAL_MAP),
LintId::of(&manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE),
LintId::of(&manual_strip::MANUAL_STRIP),
LintId::of(&manual_unwrap_or::MANUAL_UNWRAP_OR),
@ -1774,6 +1775,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&loops::WHILE_LET_ON_ITERATOR),
LintId::of(&main_recursion::MAIN_RECURSION),
LintId::of(&manual_async_fn::MANUAL_ASYNC_FN),
LintId::of(&manual_map::MANUAL_MAP),
LintId::of(&manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE),
LintId::of(&map_clone::MAP_CLONE),
LintId::of(&matches::INFALLIBLE_DESTRUCTURING_MATCH),
@ -2050,7 +2052,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(&floating_point_arithmetic::SUBOPTIMAL_FLOPS),
LintId::of(&future_not_send::FUTURE_NOT_SEND),
LintId::of(&let_if_seq::USELESS_LET_IF_SEQ),
LintId::of(&manual_map::MANUAL_MAP),
LintId::of(&missing_const_for_fn::MISSING_CONST_FOR_FN),
LintId::of(&mutable_debug_assertion::DEBUG_ASSERT_WITH_MUT_CALL),
LintId::of(&mutex_atomic::MUTEX_INTEGER),

View file

@ -2,24 +2,32 @@ use crate::{
map_unit_fn::OPTION_MAP_UNIT_FN,
matches::MATCH_AS_REF,
utils::{
is_allowed, is_type_diagnostic_item, match_def_path, match_var, paths, peel_hir_expr_refs,
peel_mid_ty_refs_is_mutable, snippet_with_applicability, span_lint_and_sugg,
can_partially_move_ty, is_allowed, is_type_diagnostic_item, match_def_path, match_var, paths,
peel_hir_expr_refs, peel_mid_ty_refs_is_mutable, snippet_with_applicability, snippet_with_context,
span_lint_and_sugg,
},
};
use rustc_ast::util::parser::PREC_POSTFIX;
use rustc_errors::Applicability;
use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, Mutability, Pat, PatKind, QPath};
use rustc_hir::{
def::Res,
intravisit::{walk_expr, ErasedMap, NestedVisitorMap, Visitor},
Arm, BindingAnnotation, Block, Expr, ExprKind, Mutability, Pat, PatKind, Path, QPath,
};
use rustc_lint::{LateContext, LateLintPass, LintContext};
use rustc_middle::lint::in_external_macro;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::symbol::{sym, Ident};
use rustc_span::{
symbol::{sym, Ident},
SyntaxContext,
};
declare_clippy_lint! {
/// **What it does:** Checks for usages of `match` which could be implemented using `map`
///
/// **Why is this bad?** Using the `map` method is clearer and more concise.
///
/// **Known problems:** `map` is not capable of representing some control flow which works fine in `match`.
/// **Known problems:** None.
///
/// **Example:**
///
@ -34,7 +42,7 @@ declare_clippy_lint! {
/// Some(0).map(|x| x + 1);
/// ```
pub MANUAL_MAP,
nursery,
style,
"reimplementation of `map`"
}
@ -52,43 +60,46 @@ impl LateLintPass<'_> for ManualMap {
{
let (scrutinee_ty, ty_ref_count, ty_mutability) =
peel_mid_ty_refs_is_mutable(cx.typeck_results().expr_ty(scrutinee));
if !is_type_diagnostic_item(cx, scrutinee_ty, sym::option_type)
|| !is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::option_type)
if !(is_type_diagnostic_item(cx, scrutinee_ty, sym::option_type)
&& is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(expr), sym::option_type))
{
return;
}
let (some_expr, some_pat, pat_ref_count, is_wild_none) =
match (try_parse_pattern(cx, arm1.pat), try_parse_pattern(cx, arm2.pat)) {
(Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count }))
if is_none_expr(cx, arm1.body) =>
{
(arm2.body, pattern, ref_count, true)
},
(Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count }))
if is_none_expr(cx, arm1.body) =>
{
(arm2.body, pattern, ref_count, false)
},
(Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild))
if is_none_expr(cx, arm2.body) =>
{
(arm1.body, pattern, ref_count, true)
},
(Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None))
if is_none_expr(cx, arm2.body) =>
{
(arm1.body, pattern, ref_count, false)
},
_ => return,
};
let expr_ctxt = expr.span.ctxt();
let (some_expr, some_pat, pat_ref_count, is_wild_none) = match (
try_parse_pattern(cx, arm1.pat, expr_ctxt),
try_parse_pattern(cx, arm2.pat, expr_ctxt),
) {
(Some(OptionPat::Wild), Some(OptionPat::Some { pattern, ref_count }))
if is_none_expr(cx, arm1.body) =>
{
(arm2.body, pattern, ref_count, true)
},
(Some(OptionPat::None), Some(OptionPat::Some { pattern, ref_count }))
if is_none_expr(cx, arm1.body) =>
{
(arm2.body, pattern, ref_count, false)
},
(Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::Wild))
if is_none_expr(cx, arm2.body) =>
{
(arm1.body, pattern, ref_count, true)
},
(Some(OptionPat::Some { pattern, ref_count }), Some(OptionPat::None))
if is_none_expr(cx, arm2.body) =>
{
(arm1.body, pattern, ref_count, false)
},
_ => return,
};
// Top level or patterns aren't allowed in closures.
if matches!(some_pat.kind, PatKind::Or(_)) {
return;
}
let some_expr = match get_some_expr(cx, some_expr) {
let some_expr = match get_some_expr(cx, some_expr, expr_ctxt) {
Some(expr) => expr,
None => return,
};
@ -99,6 +110,10 @@ impl LateLintPass<'_> for ManualMap {
return;
}
if !can_move_expr_to_closure(cx, some_expr) {
return;
}
// Determine which binding mode to use.
let explicit_ref = some_pat.contains_explicit_ref_binding();
let binding_ref = explicit_ref.or_else(|| (ty_ref_count != pat_ref_count).then(|| ty_mutability));
@ -111,47 +126,50 @@ impl LateLintPass<'_> for ManualMap {
let mut app = Applicability::MachineApplicable;
// Remove address-of expressions from the scrutinee. `as_ref` will be called,
// the type is copyable, or the option is being passed by value.
// Remove address-of expressions from the scrutinee. Either `as_ref` will be called, or
// it's being passed by value.
let scrutinee = peel_hir_expr_refs(scrutinee).0;
let scrutinee_str = snippet_with_applicability(cx, scrutinee.span, "_", &mut app);
let scrutinee_str = if expr.precedence().order() < PREC_POSTFIX {
// Parens are needed to chain method calls.
format!("({})", scrutinee_str)
} else {
scrutinee_str.into()
};
let scrutinee_str = snippet_with_context(cx, scrutinee.span, expr_ctxt, "..", &mut app);
let scrutinee_str =
if scrutinee.span.ctxt() == expr.span.ctxt() && scrutinee.precedence().order() < PREC_POSTFIX {
format!("({})", scrutinee_str)
} else {
scrutinee_str.into()
};
let body_str = if let PatKind::Binding(annotation, _, some_binding, None) = some_pat.kind {
if let Some(func) = can_pass_as_func(cx, some_binding, some_expr) {
snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
} else {
if match_var(some_expr, some_binding.name)
&& !is_allowed(cx, MATCH_AS_REF, expr.hir_id)
&& binding_ref.is_some()
{
return;
}
match can_pass_as_func(cx, some_binding, some_expr) {
Some(func) if func.span.ctxt() == some_expr.span.ctxt() => {
snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
},
_ => {
if match_var(some_expr, some_binding.name)
&& !is_allowed(cx, MATCH_AS_REF, expr.hir_id)
&& binding_ref.is_some()
{
return;
}
// `ref` and `ref mut` annotations were handled earlier.
let annotation = if matches!(annotation, BindingAnnotation::Mutable) {
"mut "
} else {
""
};
format!(
"|{}{}| {}",
annotation,
some_binding,
snippet_with_applicability(cx, some_expr.span, "..", &mut app)
)
// `ref` and `ref mut` annotations were handled earlier.
let annotation = if matches!(annotation, BindingAnnotation::Mutable) {
"mut "
} else {
""
};
format!(
"|{}{}| {}",
annotation,
some_binding,
snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app)
)
},
}
} else if !is_wild_none && explicit_ref.is_none() {
// TODO: handle explicit reference annotations.
format!(
"|{}| {}",
snippet_with_applicability(cx, some_pat.span, "..", &mut app),
snippet_with_applicability(cx, some_expr.span, "..", &mut app)
snippet_with_context(cx, some_pat.span, expr_ctxt, "..", &mut app),
snippet_with_context(cx, some_expr.span, expr_ctxt, "..", &mut app)
)
} else {
// Refutable bindings and mixed reference annotations can't be handled by `map`.
@ -171,6 +189,51 @@ impl LateLintPass<'_> for ManualMap {
}
}
// Checks if the expression can be moved into a closure as is.
fn can_move_expr_to_closure(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> bool {
struct V<'cx, 'tcx> {
cx: &'cx LateContext<'tcx>,
make_closure: bool,
}
impl Visitor<'tcx> for V<'_, 'tcx> {
type Map = ErasedMap<'tcx>;
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::None
}
fn visit_expr(&mut self, e: &'tcx Expr<'_>) {
match e.kind {
ExprKind::Break(..)
| ExprKind::Continue(_)
| ExprKind::Ret(_)
| ExprKind::Yield(..)
| ExprKind::InlineAsm(_)
| ExprKind::LlvmInlineAsm(_) => {
self.make_closure = false;
},
// Accessing a field of a local value can only be done if the type isn't
// partially moved.
ExprKind::Field(base_expr, _)
if matches!(
base_expr.kind,
ExprKind::Path(QPath::Resolved(_, Path { res: Res::Local(_), .. }))
) && can_partially_move_ty(self.cx, self.cx.typeck_results().expr_ty(base_expr)) =>
{
// TODO: check if the local has been partially moved. Assume it has for now.
self.make_closure = false;
return;
}
_ => (),
};
walk_expr(self, e);
}
}
let mut v = V { cx, make_closure: true };
v.visit_expr(expr);
v.make_closure
}
// Checks whether the expression could be passed as a function, or whether a closure is needed.
// Returns the function to be passed to `map` if it exists.
fn can_pass_as_func(cx: &LateContext<'tcx>, binding: Ident, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
@ -198,11 +261,11 @@ enum OptionPat<'a> {
// Try to parse into a recognized `Option` pattern.
// i.e. `_`, `None`, `Some(..)`, or a reference to any of those.
fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) -> Option<OptionPat<'tcx>> {
fn f(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ref_count: usize) -> Option<OptionPat<'tcx>> {
fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
fn f(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, ref_count: usize, ctxt: SyntaxContext) -> Option<OptionPat<'tcx>> {
match pat.kind {
PatKind::Wild => Some(OptionPat::Wild),
PatKind::Ref(pat, _) => f(cx, pat, ref_count + 1),
PatKind::Ref(pat, _) => f(cx, pat, ref_count + 1, ctxt),
PatKind::Path(QPath::Resolved(None, path))
if path
.res
@ -215,18 +278,19 @@ fn try_parse_pattern(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>) -> Option<Optio
if path
.res
.opt_def_id()
.map_or(false, |id| match_def_path(cx, id, &paths::OPTION_SOME)) =>
.map_or(false, |id| match_def_path(cx, id, &paths::OPTION_SOME))
&& pat.span.ctxt() == ctxt =>
{
Some(OptionPat::Some { pattern, ref_count })
},
_ => None,
}
}
f(cx, pat, 0)
f(cx, pat, 0, ctxt)
}
// Checks for an expression wrapped by the `Some` constructor. Returns the contained expression.
fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, ctxt: SyntaxContext) -> Option<&'tcx Expr<'tcx>> {
// TODO: Allow more complex expressions.
match expr.kind {
ExprKind::Call(
@ -235,7 +299,7 @@ fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx E
..
},
[arg],
) => {
) if ctxt == expr.span.ctxt() => {
if match_def_path(cx, path.res.opt_def_id()?, &paths::OPTION_SOME) {
Some(arg)
} else {
@ -249,7 +313,7 @@ fn get_some_expr(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) -> Option<&'tcx E
..
},
_,
) => get_some_expr(cx, expr),
) => get_some_expr(cx, expr, ctxt),
_ => None,
}
}

View file

@ -73,11 +73,11 @@ use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
use rustc_middle::ty::{self, layout::IntegerExt, DefIdTree, Ty, TyCtxt, TypeFoldable};
use rustc_semver::RustcVersion;
use rustc_session::Session;
use rustc_span::hygiene::{ExpnKind, MacroKind};
use rustc_span::hygiene::{self, ExpnKind, MacroKind};
use rustc_span::source_map::original_sp;
use rustc_span::sym;
use rustc_span::symbol::{kw, Symbol};
use rustc_span::{BytePos, Pos, Span, DUMMY_SP};
use rustc_span::{BytePos, Pos, Span, SyntaxContext, DUMMY_SP};
use rustc_target::abi::Integer;
use rustc_trait_selection::traits::query::normalize::AtExt;
use smallvec::SmallVec;
@ -472,6 +472,18 @@ pub fn has_drop<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
}
}
/// Checks whether a type can be partially moved.
pub fn can_partially_move_ty(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
if has_drop(cx, ty) || is_copy(cx, ty) {
return false;
}
match ty.kind() {
ty::Param(_) => false,
ty::Adt(def, subs) => def.all_fields().any(|f| !is_copy(cx, f.ty(cx.tcx, subs))),
_ => true,
}
}
/// Returns the method names and argument list of nested method call expressions that make up
/// `expr`. method/span lists are sorted with the most recent call first.
pub fn method_calls<'tcx>(
@ -762,6 +774,35 @@ pub fn snippet_block_with_applicability<'a, T: LintContext>(
reindent_multiline(snip, true, indent)
}
/// Same as `snippet_with_applicability`, but first walks the span up to the given context. This
/// will result in the macro call, rather then the expansion, if the span is from a child context.
/// If the span is not from a child context, it will be used directly instead.
///
/// e.g. Given the expression `&vec![]`, getting a snippet from the span for `vec![]` as a HIR node
/// would result in `box []`. If given the context of the address of expression, this function will
/// correctly get a snippet of `vec![]`.
pub fn snippet_with_context(
cx: &LateContext<'_>,
span: Span,
outer: SyntaxContext,
default: &'a str,
applicability: &mut Applicability,
) -> Cow<'a, str> {
let outer_span = hygiene::walk_chain(span, outer);
let span = if outer_span.ctxt() == outer {
outer_span
} else {
// The span is from a macro argument, and the outer context is the macro using the argument
if *applicability != Applicability::Unspecified {
*applicability = Applicability::MaybeIncorrect;
}
// TODO: get the argument span.
span
};
snippet_with_applicability(cx, span, default, applicability)
}
/// Returns a new Span that extends the original Span to the first non-whitespace char of the first
/// line.
///

View file

@ -1,7 +1,14 @@
// edition:2018
// run-rustfix
#![warn(clippy::manual_map)]
#![allow(clippy::no_effect, clippy::map_identity, clippy::unit_arg, clippy::match_ref_pats)]
#![allow(
clippy::no_effect,
clippy::map_identity,
clippy::unit_arg,
clippy::match_ref_pats,
dead_code
)]
fn main() {
Some(0).map(|_| 2);
@ -67,4 +74,58 @@ fn main() {
Some(Some((x, 1))) => Some(x),
_ => None,
};
// #6795
fn f1() -> Result<(), ()> {
let _ = match Some(Ok(())) {
Some(x) => Some(x?),
None => None,
};
Ok(())
}
for &x in Some(Some(true)).iter() {
let _ = match x {
Some(x) => Some(if x { continue } else { x }),
None => None,
};
}
// #6797
let x1 = (Some(String::new()), 0);
let x2 = x1.0;
match x2 {
Some(x) => Some((x, x1.1)),
None => None,
};
struct S1 {
x: Option<String>,
y: u32,
}
impl S1 {
fn f(self) -> Option<(String, u32)> {
match self.x {
Some(x) => Some((x, self.y)),
None => None,
}
}
}
// #6811
Some(0).map(|x| vec![x]);
option_env!("").map(String::from);
// #6819
async fn f2(x: u32) -> u32 {
x
}
async fn f3() {
match Some(0) {
Some(x) => Some(f2(x).await),
None => None,
};
}
}

View file

@ -1,7 +1,14 @@
// edition:2018
// run-rustfix
#![warn(clippy::manual_map)]
#![allow(clippy::no_effect, clippy::map_identity, clippy::unit_arg, clippy::match_ref_pats)]
#![allow(
clippy::no_effect,
clippy::map_identity,
clippy::unit_arg,
clippy::match_ref_pats,
dead_code
)]
fn main() {
match Some(0) {
@ -119,4 +126,64 @@ fn main() {
Some(Some((x, 1))) => Some(x),
_ => None,
};
// #6795
fn f1() -> Result<(), ()> {
let _ = match Some(Ok(())) {
Some(x) => Some(x?),
None => None,
};
Ok(())
}
for &x in Some(Some(true)).iter() {
let _ = match x {
Some(x) => Some(if x { continue } else { x }),
None => None,
};
}
// #6797
let x1 = (Some(String::new()), 0);
let x2 = x1.0;
match x2 {
Some(x) => Some((x, x1.1)),
None => None,
};
struct S1 {
x: Option<String>,
y: u32,
}
impl S1 {
fn f(self) -> Option<(String, u32)> {
match self.x {
Some(x) => Some((x, self.y)),
None => None,
}
}
}
// #6811
match Some(0) {
Some(x) => Some(vec![x]),
None => None,
};
match option_env!("") {
Some(x) => Some(String::from(x)),
None => None,
};
// #6819
async fn f2(x: u32) -> u32 {
x
}
async fn f3() {
match Some(0) {
Some(x) => Some(f2(x).await),
None => None,
};
}
}

View file

@ -1,5 +1,5 @@
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:7:5
--> $DIR/manual_map_option.rs:14:5
|
LL | / match Some(0) {
LL | | Some(_) => Some(2),
@ -10,7 +10,7 @@ LL | | };
= note: `-D clippy::manual-map` implied by `-D warnings`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:12:5
--> $DIR/manual_map_option.rs:19:5
|
LL | / match Some(0) {
LL | | Some(x) => Some(x + 1),
@ -19,7 +19,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| x + 1)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:17:5
--> $DIR/manual_map_option.rs:24:5
|
LL | / match Some("") {
LL | | Some(x) => Some(x.is_empty()),
@ -28,7 +28,7 @@ LL | | };
| |_____^ help: try this: `Some("").map(|x| x.is_empty())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:22:5
--> $DIR/manual_map_option.rs:29:5
|
LL | / if let Some(x) = Some(0) {
LL | | Some(!x)
@ -38,7 +38,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| !x)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:29:5
--> $DIR/manual_map_option.rs:36:5
|
LL | / match Some(0) {
LL | | Some(x) => { Some(std::convert::identity(x)) }
@ -47,7 +47,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(std::convert::identity)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:34:5
--> $DIR/manual_map_option.rs:41:5
|
LL | / match Some(&String::new()) {
LL | | Some(x) => Some(str::len(x)),
@ -56,7 +56,7 @@ LL | | };
| |_____^ help: try this: `Some(&String::new()).map(|x| str::len(x))`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:44:5
--> $DIR/manual_map_option.rs:51:5
|
LL | / match &Some([0, 1]) {
LL | | Some(x) => Some(x[0]),
@ -65,7 +65,7 @@ LL | | };
| |_____^ help: try this: `Some([0, 1]).as_ref().map(|x| x[0])`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:49:5
--> $DIR/manual_map_option.rs:56:5
|
LL | / match &Some(0) {
LL | | &Some(x) => Some(x * 2),
@ -74,7 +74,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| x * 2)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:54:5
--> $DIR/manual_map_option.rs:61:5
|
LL | / match Some(String::new()) {
LL | | Some(ref x) => Some(x.is_empty()),
@ -83,7 +83,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:59:5
--> $DIR/manual_map_option.rs:66:5
|
LL | / match &&Some(String::new()) {
LL | | Some(x) => Some(x.len()),
@ -92,7 +92,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:64:5
--> $DIR/manual_map_option.rs:71:5
|
LL | / match &&Some(0) {
LL | | &&Some(x) => Some(x + x),
@ -101,7 +101,7 @@ LL | | };
| |_____^ help: try this: `Some(0).map(|x| x + x)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:77:9
--> $DIR/manual_map_option.rs:84:9
|
LL | / match &mut Some(String::new()) {
LL | | Some(x) => Some(x.push_str("")),
@ -110,7 +110,7 @@ LL | | };
| |_________^ help: try this: `Some(String::new()).as_mut().map(|x| x.push_str(""))`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:83:5
--> $DIR/manual_map_option.rs:90:5
|
LL | / match &mut Some(String::new()) {
LL | | Some(ref x) => Some(x.len()),
@ -119,7 +119,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:88:5
--> $DIR/manual_map_option.rs:95:5
|
LL | / match &mut &Some(String::new()) {
LL | | Some(x) => Some(x.is_empty()),
@ -128,7 +128,7 @@ LL | | };
| |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:93:5
--> $DIR/manual_map_option.rs:100:5
|
LL | / match Some((0, 1, 2)) {
LL | | Some((x, y, z)) => Some(x + y + z),
@ -137,7 +137,7 @@ LL | | };
| |_____^ help: try this: `Some((0, 1, 2)).map(|(x, y, z)| x + y + z)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:98:5
--> $DIR/manual_map_option.rs:105:5
|
LL | / match Some([1, 2, 3]) {
LL | | Some([first, ..]) => Some(first),
@ -146,7 +146,7 @@ LL | | };
| |_____^ help: try this: `Some([1, 2, 3]).map(|[first, ..]| first)`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:103:5
--> $DIR/manual_map_option.rs:110:5
|
LL | / match &Some((String::new(), "test")) {
LL | | Some((x, y)) => Some((y, x)),
@ -154,5 +154,23 @@ LL | | None => None,
LL | | };
| |_____^ help: try this: `Some((String::new(), "test")).as_ref().map(|(x, y)| (y, x))`
error: aborting due to 17 previous errors
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:168:5
|
LL | / match Some(0) {
LL | | Some(x) => Some(vec![x]),
LL | | None => None,
LL | | };
| |_____^ help: try this: `Some(0).map(|x| vec![x])`
error: manual implementation of `Option::map`
--> $DIR/manual_map_option.rs:173:5
|
LL | / match option_env!("") {
LL | | Some(x) => Some(String::from(x)),
LL | | None => None,
LL | | };
| |_____^ help: try this: `option_env!("").map(String::from)`
error: aborting due to 19 previous errors