Merge pull request #23 from QiangHeisenberg/rust

流程控制、字符串、集合容器三个章节的lint信息修改

Author: ZhangHanDong

src/safe-guides/coding_practice/control-flow.md

@@ -434,7 +434,7 @@ if !sad_people.is_empty() {
 | [filter_map_identity](https://rust-lang.github.io/rust-clippy/master/#filter_map_identity) | yes           | no           | complexity | warn  |
 | [filter_next](https://rust-lang.github.io/rust-clippy/master/#filter_next) | yes           | no           | complexity | warn  |
 | [flat_map_identity](https://rust-lang.github.io/rust-clippy/master/#flat_map_identity) | yes           | no           | complexity | warn  |
-| [flat_map_option](https://rust-lang.github.io/rust-clippy/master/#flat_map_option) | yes           | no           | complexity | warn  |
+| [flat_map_option](https://rust-lang.github.io/rust-clippy/master/#flat_map_option) | yes           | no           | pedantic | allow  |
 
 ### 【描述】
 

src/safe-guides/coding_practice/strings.md

@@ -156,7 +156,7 @@ pub fn find<'a, S: Into<Cow<'a, str>>>(input: S) -> Cow<'a, str> {
 
 | lint name                                                    | Clippy 可检测 | Rustc 可检测 | Lint Group | level |
 | ------------------------------------------------------------ | ------------- | ------------ | ---------- | ----- |
-| [to_string_in_display](https://rust-lang.github.io/rust-clippy/master/#to_string_in_display) | yes           | no           | complexity | warn  |
+| [to_string_in_display](https://rust-lang.github.io/rust-clippy/master/#to_string_in_display) | yes           | no           | correctness | deny |
 
 ### 【描述】
 
@@ -232,7 +232,7 @@ x = x + ", World";
 
 | lint name                                                    | Clippy 可检测 | Rustc 可检测 | Lint Group | level |
 | ------------------------------------------------------------ | ------------- | ------------ | ---------- | ----- |
-| [string_lit_as_bytes](https://rust-lang.github.io/rust-clippy/master/#string_lit_as_bytes) | yes           | no           | complexity | warn  |
+| [string_lit_as_bytes](https://rust-lang.github.io/rust-clippy/master/#string_lit_as_bytes) | yes           | no           | nursery | allow |
 
 ### 【描述】