Fix more code examples

Author: ThibsG

clippy_lints/src/fallible_impl_from.rs

@@ -18,13 +18,24 @@ declare_clippy_lint! {
     /// **Known problems:** None.
     ///
     /// **Example:**
-    /// ```rust
+    /// ```rust,ignore
     /// struct Foo(i32);
+    ///
+    /// // Bad
     /// impl From<String> for Foo {
     ///     fn from(s: String) -> Self {
     ///         Foo(s.parse().unwrap())
     ///     }
     /// }
+    ///
+    /// // Good
+    /// use std::convert::TryFrom;
+    /// impl TryFrom<String> for Foo {
+    ///     type Error = ();
+    ///     fn try_from(s: String) -> Result<Self, Self::Error> {
+    ///         s.parse()
+    ///     }
+    /// }
     /// ```
     pub FALLIBLE_IMPL_FROM,
     nursery,
@@ -120,7 +131,7 @@ fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_it
                         move |diag| {
                             diag.help(
                                 "`From` is intended for infallible conversions only. \
-                                 Use `TryFrom` if there's a possibility for the conversion to fail.");
+                                Use `TryFrom` if there's a possibility for the conversion to fail.");
                             diag.span_note(fpu.result, "potential failure(s)");
                         });
                 }

clippy_lints/src/floating_point_arithmetic.rs

@@ -28,7 +28,6 @@ declare_clippy_lint! {
     /// **Example:**
     ///
     /// ```rust
-    ///
     /// let a = 3f32;
     /// let _ = a.powf(1.0 / 3.0);
     /// let _ = (1.0 + a).ln();
@@ -38,7 +37,6 @@ declare_clippy_lint! {
     /// is better expressed as
     ///
     /// ```rust
-    ///
     /// let a = 3f32;
     /// let _ = a.cbrt();
     /// let _ = a.ln_1p();

clippy_lints/src/format.rs

@@ -25,9 +25,13 @@ declare_clippy_lint! {
     ///
     /// **Examples:**
     /// ```rust
+    ///
+    /// // Bad
     /// # let foo = "foo";
-    /// format!("foo");
     /// format!("{}", foo);
+    ///
+    /// // Good
+    /// format!("foo");
     /// ```
     pub USELESS_FORMAT,
     complexity,

clippy_lints/src/functions.rs

@@ -49,11 +49,11 @@ declare_clippy_lint! {
     /// **Known problems:** None.
     ///
     /// **Example:**
-    /// ``` rust
+    /// ```rust
     /// fn im_too_long() {
-    /// println!("");
+    ///     println!("");
     /// // ... 100 more LoC
-    /// println!("");
+    ///     println!("");
     /// }
     /// ```
     pub TOO_MANY_LINES,
@@ -79,10 +79,16 @@ declare_clippy_lint! {
     /// `some_argument.get_raw_ptr()`).
     ///
     /// **Example:**
-    /// ```rust
+    /// ```rust,ignore
+    /// // Bad
     /// pub fn foo(x: *const u8) {
     ///     println!("{}", unsafe { *x });
     /// }
+    ///
+    /// // Good
+    /// pub unsafe fn foo(x: *const u8) {
+    ///     println!("{}", unsafe { *x });
+    /// }
     /// ```
     pub NOT_UNSAFE_PTR_ARG_DEREF,
     correctness,

clippy_lints/src/implicit_saturating_sub.rs

@@ -25,13 +25,6 @@ declare_clippy_lint! {
     /// if i != 0 {
     ///     i -= 1;
     /// }
-    /// ```
-    /// Use instead:
-    /// ```rust
-    /// let end: u32 = 10;
-    /// let start: u32 = 5;
-    ///
-    /// let mut i: u32 = end - start;
     ///
     /// // Good
     /// i = i.saturating_sub(1);

clippy_lints/src/int_plus_one.rs

@@ -10,7 +10,6 @@ use crate::utils::{snippet_opt, span_lint_and_sugg};
 declare_clippy_lint! {
     /// **What it does:** Checks for usage of `x >= y + 1` or `x - 1 >= y` (and `<=`) in a block
     ///
-    ///
     /// **Why is this bad?** Readability -- better to use `> y` instead of `>= y + 1`.
     ///
     /// **Known problems:** None.

clippy_lints/src/integer_division.rs

@@ -15,10 +15,13 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
-    /// fn main() {
-    ///     let x = 3 / 2;
-    ///     println!("{}", x);
-    /// }
+    /// // Bad
+    /// let x = 3 / 2;
+    /// println!("{}", x);
+    ///
+    /// // Good
+    /// let x = 3f32 / 2f32;
+    /// println!("{}", x);
     /// ```
     pub INTEGER_DIVISION,
     restriction,

clippy_lints/src/items_after_statements.rs

@@ -16,6 +16,7 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
+    /// // Bad
     /// fn foo() {
     ///     println!("cake");
     /// }
@@ -28,6 +29,21 @@ declare_clippy_lint! {
     ///     foo(); // prints "foo"
     /// }
     /// ```
+    ///
+    /// ```rust
+    /// // Good
+    /// fn foo() {
+    ///     println!("cake");
+    /// }
+    ///
+    /// fn main() {
+    ///     fn foo() {
+    ///         println!("foo");
+    ///     }
+    ///     foo(); // prints "foo"
+    ///     foo(); // prints "foo"
+    /// }
+    /// ```
     pub ITEMS_AFTER_STATEMENTS,
     pedantic,
     "blocks where an item comes after a statement"