* [`map_err_ignore`] [#5998](https://github.com/rust-lang/rust-clippy/pull/5998)
* [`rc_buffer`] [#6044](https://github.com/rust-lang/rust-clippy/pull/6044)
* [`to_string_in_display`] [#5831](https://github.com/rust-lang/rust-clippy/pull/5831)
-* [`single_char_push_str`] [#5881](https://github.com/rust-lang/rust-clippy/pull/5881)
+* `single_char_push_str` [#5881](https://github.com/rust-lang/rust-clippy/pull/5881)
### Moves and Deprecations
[`assign_ops`]: https://rust-lang.github.io/rust-clippy/master/index.html#assign_ops
[`async_yields_async`]: https://rust-lang.github.io/rust-clippy/master/index.html#async_yields_async
[`await_holding_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_lock
+[`await_holding_refcell_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#await_holding_refcell_ref
[`bad_bit_mask`]: https://rust-lang.github.io/rust-clippy/master/index.html#bad_bit_mask
[`bind_instead_of_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#bind_instead_of_map
[`blacklisted_name`]: https://rust-lang.github.io/rust-clippy/master/index.html#blacklisted_name
[`cognitive_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity
[`collapsible_if`]: https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
[`comparison_chain`]: https://rust-lang.github.io/rust-clippy/master/index.html#comparison_chain
+[`comparison_to_empty`]: https://rust-lang.github.io/rust-clippy/master/index.html#comparison_to_empty
[`copy_iterator`]: https://rust-lang.github.io/rust-clippy/master/index.html#copy_iterator
[`create_dir`]: https://rust-lang.github.io/rust-clippy/master/index.html#create_dir
[`crosspointer_transmute`]: https://rust-lang.github.io/rust-clippy/master/index.html#crosspointer_transmute
[`extend_from_slice`]: https://rust-lang.github.io/rust-clippy/master/index.html#extend_from_slice
[`extra_unused_lifetimes`]: https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes
[`fallible_impl_from`]: https://rust-lang.github.io/rust-clippy/master/index.html#fallible_impl_from
+[`field_reassign_with_default`]: https://rust-lang.github.io/rust-clippy/master/index.html#field_reassign_with_default
[`filetype_is_file`]: https://rust-lang.github.io/rust-clippy/master/index.html#filetype_is_file
[`filter_map`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map
[`filter_map_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#filter_map_next
[`for_loops_over_fallibles`]: https://rust-lang.github.io/rust-clippy/master/index.html#for_loops_over_fallibles
[`forget_copy`]: https://rust-lang.github.io/rust-clippy/master/index.html#forget_copy
[`forget_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#forget_ref
+[`from_iter_instead_of_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#from_iter_instead_of_collect
[`future_not_send`]: https://rust-lang.github.io/rust-clippy/master/index.html#future_not_send
[`get_last_with_len`]: https://rust-lang.github.io/rust-clippy/master/index.html#get_last_with_len
[`get_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[`large_digit_groups`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_digit_groups
[`large_enum_variant`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_enum_variant
[`large_stack_arrays`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_stack_arrays
+[`large_types_passed_by_value`]: https://rust-lang.github.io/rust-clippy/master/index.html#large_types_passed_by_value
[`len_without_is_empty`]: https://rust-lang.github.io/rust-clippy/master/index.html#len_without_is_empty
[`len_zero`]: https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[`let_and_return`]: https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return
[`manual_async_fn`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_async_fn
[`manual_memcpy`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_memcpy
[`manual_non_exhaustive`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_non_exhaustive
+[`manual_ok_or`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_ok_or
+[`manual_range_contains`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_range_contains
[`manual_saturating_arithmetic`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_saturating_arithmetic
[`manual_strip`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_strip
[`manual_swap`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_swap
[`manual_unwrap_or`]: https://rust-lang.github.io/rust-clippy/master/index.html#manual_unwrap_or
[`many_single_char_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#many_single_char_names
[`map_clone`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_clone
+[`map_collect_result_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_collect_result_unit
[`map_entry`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_entry
[`map_err_ignore`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_err_ignore
[`map_flatten`]: https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten
[`must_use_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#must_use_unit
[`mut_from_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_from_ref
[`mut_mut`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_mut
+[`mut_mutex_lock`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_mutex_lock
[`mut_range_bound`]: https://rust-lang.github.io/rust-clippy/master/index.html#mut_range_bound
[`mutable_key_type`]: https://rust-lang.github.io/rust-clippy/master/index.html#mutable_key_type
[`mutex_atomic`]: https://rust-lang.github.io/rust-clippy/master/index.html#mutex_atomic
[`redundant_pub_crate`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pub_crate
[`redundant_static_lifetimes`]: https://rust-lang.github.io/rust-clippy/master/index.html#redundant_static_lifetimes
[`ref_in_deref`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_in_deref
+[`ref_option_ref`]: https://rust-lang.github.io/rust-clippy/master/index.html#ref_option_ref
[`regex_macro`]: https://rust-lang.github.io/rust-clippy/master/index.html#regex_macro
[`repeat_once`]: https://rust-lang.github.io/rust-clippy/master/index.html#repeat_once
[`replace_consts`]: https://rust-lang.github.io/rust-clippy/master/index.html#replace_consts
[`should_assert_eq`]: https://rust-lang.github.io/rust-clippy/master/index.html#should_assert_eq
[`should_implement_trait`]: https://rust-lang.github.io/rust-clippy/master/index.html#should_implement_trait
[`similar_names`]: https://rust-lang.github.io/rust-clippy/master/index.html#similar_names
+[`single_char_add_str`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_add_str
[`single_char_pattern`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_pattern
-[`single_char_push_str`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_char_push_str
[`single_component_path_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_component_path_imports
+[`single_element_loop`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
[`single_match`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match
[`single_match_else`]: https://rust-lang.github.io/rust-clippy/master/index.html#single_match_else
[`skip_while_next`]: https://rust-lang.github.io/rust-clippy/master/index.html#skip_while_next
[`try_err`]: https://rust-lang.github.io/rust-clippy/master/index.html#try_err
[`type_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
[`type_repetition_in_bounds`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_repetition_in_bounds
+[`undropped_manually_drops`]: https://rust-lang.github.io/rust-clippy/master/index.html#undropped_manually_drops
[`unicode_not_nfc`]: https://rust-lang.github.io/rust-clippy/master/index.html#unicode_not_nfc
[`unimplemented`]: https://rust-lang.github.io/rust-clippy/master/index.html#unimplemented
[`uninit_assumed_init`]: https://rust-lang.github.io/rust-clippy/master/index.html#uninit_assumed_init
[`unused_label`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_label
[`unused_self`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_self
[`unused_unit`]: https://rust-lang.github.io/rust-clippy/master/index.html#unused_unit
+[`unusual_byte_groupings`]: https://rust-lang.github.io/rust-clippy/master/index.html#unusual_byte_groupings
[`unwrap_in_result`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_in_result
[`unwrap_used`]: https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_used
[`use_debug`]: https://rust-lang.github.io/rust-clippy/master/index.html#use_debug