Ignore mismatched_lifetime_syntaxes lint

    warning: lifetime flowing from input to output with different syntax can be confusing
      --> macro/src/generics.rs:70:43
       |
    70 |     pub(crate) fn to_underscore_lifetimes(&self) -> UnderscoreLifetimes {
       |                                           ^^^^^     ------------------- the lifetime gets resolved as `'_`
       |                                           |
       |                                           this lifetime flows to the output
       |
       = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
       |
    70 |     pub(crate) fn to_underscore_lifetimes(&self) -> UnderscoreLifetimes<'_> {
       |                                                                        ++++

    warning: lifetime flowing from input to output with different syntax can be confusing
      --> syntax/instantiate.rs:30:28
       |
    30 |     pub(crate) fn impl_key(&self) -> Option<ImplKey> {
       |                            ^^^^^            ------- the lifetime gets resolved as `'_`
       |                            |
       |                            this lifetime flows to the output
       |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
       |
    30 |     pub(crate) fn impl_key(&self) -> Option<ImplKey<'_>> {
       |                                                    ++++

    warning: lifetime flowing from input to output with different syntax can be confusing
      --> syntax/map.rs:29:28
       |
    29 |         pub(crate) fn iter(&self) -> Iter<K, V> {
       |                            ^^^^^     ---------- the lifetime gets resolved as `'_`
       |                            |
       |                            this lifetime flows to the output
       |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
       |
    29 |         pub(crate) fn iter(&self) -> Iter<'_, K, V> {
       |                                           +++

    warning: lifetime flowing from input to output with different syntax can be confusing
       --> syntax/map.rs:115:29
        |
    115 |         pub(crate) fn entry(&mut self, key: K) -> Entry<K, V> {
        |                             ^^^^^^^^^             ----------- the lifetime gets resolved as `'_`
        |                             |
        |                             this lifetime flows to the output
        |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
        |
    115 |         pub(crate) fn entry(&mut self, key: K) -> Entry<'_, K, V> {
        |                                                         +++

    warning: lifetime flowing from input to output with different syntax can be confusing
      --> syntax/namespace.rs:22:24
       |
    22 |     pub(crate) fn iter(&self) -> Iter<Ident> {
       |                        ^^^^^     ----------- the lifetime gets resolved as `'_`
       |                        |
       |                        this lifetime flows to the output
       |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
       |
    22 |     pub(crate) fn iter(&self) -> Iter<'_, Ident> {
       |                                       +++

    warning: lifetime flowing from input to output with different syntax can be confusing
      --> macro/src/tokens.rs:11:22
       |
    11 |     pub(crate) fn ty(&self) -> ReceiverType {
       |                      ^^^^^     ------------ the lifetime gets resolved as `'_`
       |                      |
       |                      this lifetime flows to the output
       |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
       |
    11 |     pub(crate) fn ty(&self) -> ReceiverType<'_> {
       |                                            ++++

    warning: lifetime flowing from input to output with different syntax can be confusing
      --> macro/src/tokens.rs:16:27
       |
    16 |     pub(crate) fn ty_self(&self) -> ReceiverTypeSelf {
       |                           ^^^^^     ---------------- the lifetime gets resolved as `'_`
       |                           |
       |                           this lifetime flows to the output
       |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
       |
    16 |     pub(crate) fn ty_self(&self) -> ReceiverTypeSelf<'_> {
       |                                                     ++++

    warning: lifetime flowing from input to output with different syntax can be confusing
       --> src/cxx_vector.rs:166:17
        |
    166 |     pub fn iter(&self) -> Iter<T> {
        |                 ^^^^^     ------- the lifetime gets resolved as `'_`
        |                 |
        |                 this lifetime flows to the output
        |
        = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
        |
    166 |     pub fn iter(&self) -> Iter<'_, T> {
        |                                +++

    warning: lifetime flowing from input to output with different syntax can be confusing
       --> src/cxx_vector.rs:171:31
        |
    171 |     pub fn iter_mut(self: Pin<&mut Self>) -> IterMut<T> {
        |                               ^^^^^^^^^      ---------- the lifetime gets resolved as `'_`
        |                               |
        |                               this lifetime flows to the output
        |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
        |
    171 |     pub fn iter_mut(self: Pin<&mut Self>) -> IterMut<'_, T> {
        |                                                      +++

    warning: lifetime flowing from input to output with different syntax can be confusing
       --> src/cxx_string.rs:169:28
        |
    169 |     pub fn to_string_lossy(&self) -> Cow<str> {
        |                            ^^^^^     -------- the lifetime gets resolved as `'_`
        |                            |
        |                            this lifetime flows to the output
        |
    help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
        |
    169 |     pub fn to_string_lossy(&self) -> Cow<'_, str> {
        |                                          +++

Author: dtolnay

gen/build/src/lib.rs

@@ -75,6 +75,7 @@
     clippy::uninlined_format_args,
     clippy::upper_case_acronyms
 )]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 mod cargo;
 mod cfg;

gen/cmd/src/main.rs

@@ -23,6 +23,7 @@
     clippy::toplevel_ref_arg,
     clippy::uninlined_format_args
 )]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 mod app;
 mod cfg;

gen/lib/src/lib.rs

@@ -36,6 +36,7 @@
     clippy::toplevel_ref_arg,
     clippy::uninlined_format_args
 )]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 mod error;
 mod gen;

macro/src/lib.rs

@@ -19,6 +19,7 @@
     clippy::toplevel_ref_arg,
     clippy::uninlined_format_args
 )]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 mod derive;
 mod expand;

src/lib.rs

@@ -395,6 +395,7 @@
     clippy::ref_as_ptr,
     clippy::uninlined_format_args
 )]
+#![allow(unknown_lints, mismatched_lifetime_syntaxes)]
 
 #[cfg(built_with_cargo)]
 extern crate link_cplusplus;

tests/ffi/lib.rs

@@ -239,6 +239,7 @@ pub mod ffi {
         fn c_return_borrow<'a>(s: &'a CxxString) -> UniquePtr<Borrow<'a>>;
 
         #[rust_name = "c_return_borrow_elided"]
+        #[allow(unknown_lints, mismatched_lifetime_syntaxes)]
         fn c_return_borrow(s: &CxxString) -> UniquePtr<Borrow>;
 
         fn const_member(self: &Borrow);

tests/ui/deny_elided_lifetimes.rs

@@ -1,4 +1,4 @@
-#![deny(elided_lifetimes_in_paths)]
+#![deny(elided_lifetimes_in_paths, mismatched_lifetime_syntaxes)]
 
 #[cxx::bridge]
 mod ffi {

tests/ui/deny_elided_lifetimes.stderr

@@ -7,9 +7,27 @@ error: hidden lifetime parameters in types are deprecated
 note: the lint level is defined here
   --> tests/ui/deny_elided_lifetimes.rs:1:9
    |
-1  | #![deny(elided_lifetimes_in_paths)]
+1  | #![deny(elided_lifetimes_in_paths, mismatched_lifetime_syntaxes)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
 help: indicate the anonymous lifetime
    |
 21 |         fn lifetime_elided(s: &i32) -> UniquePtr<Cpp<'_>>;
    |                                                     ++++
+
+error: lifetime flowing from input to output with different syntax can be confusing
+  --> tests/ui/deny_elided_lifetimes.rs:21:31
+   |
+21 |         fn lifetime_elided(s: &i32) -> UniquePtr<Cpp>;
+   |                               ^^^^               --- the lifetime gets resolved as `'_`
+   |                               |
+   |                               this lifetime flows to the output
+   |
+note: the lint level is defined here
+  --> tests/ui/deny_elided_lifetimes.rs:1:36
+   |
+1  | #![deny(elided_lifetimes_in_paths, mismatched_lifetime_syntaxes)]
+   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
+   |
+21 |         fn lifetime_elided(s: &i32) -> UniquePtr<Cpp<'_>>;
+   |                                                     ++++