Auto merge of #4325 - phansch:doctests_complexity, r=flip1995

Doctests: Enable running doc tests for complexity lints

changelog: none

master: `113 passed; 0 failed; 91 ignored; 0 measured; 0 filtered out`
this PR: `181 passed; 0 failed; 110 ignored; 0 measured; 0 filtered out`

cc #4319

Author: bors

clippy_lints/src/assign_ops.rs

@@ -45,7 +45,8 @@ declare_clippy_lint! {
     /// **Example:**
     /// ```rust
     /// let mut a = 5;
-    /// ...
+    /// let b = 2;
+    /// // ...
     /// a += a + b;
     /// ```
     pub MISREFACTORED_ASSIGN_OP,

clippy_lints/src/double_comparison.rs

@@ -18,13 +18,17 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
-    /// x == y || x < y
+    /// # let x = 1;
+    /// # let y = 2;
+    /// if x == y || x < y {}
     /// ```
     ///
     /// Could be written as:
     ///
     /// ```rust
-    /// x <= y
+    /// # let x = 1;
+    /// # let y = 2;
+    /// if x <= y {}
     /// ```
     pub DOUBLE_COMPARISONS,
     complexity,

clippy_lints/src/double_parens.rs

@@ -13,9 +13,10 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
-    /// ((0))
-    /// foo((0))
-    /// ((1, 2))
+    /// # fn foo(bar: usize) {}
+    /// ((0));
+    /// foo((0));
+    /// ((1, 2));
     /// ```
     pub DOUBLE_PARENS,
     complexity,

clippy_lints/src/duration_subsec.rs

@@ -20,6 +20,7 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
+    /// # use std::time::Duration;
     /// let dur = Duration::new(5, 0);
     /// let _micros = dur.subsec_nanos() / 1_000;
     /// let _millis = dur.subsec_nanos() / 1_000_000;

clippy_lints/src/eval_order_dependence.rs

@@ -42,7 +42,9 @@ declare_clippy_lint! {
     /// shorthand.
     ///
     /// **Example:**
-    /// ```rust
+    /// ```rust,no_run
+    /// # fn b() -> bool { true }
+    /// # fn c() -> bool { true }
     /// let a = b() || panic!() || c();
     /// // `c()` is dead, `panic!()` is only called if `b()` returns `false`
     /// let x = (a, b, c, panic!());

clippy_lints/src/explicit_write.rs

@@ -16,8 +16,10 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
+    /// # use std::io::Write;
+    /// # let bar = "furchtbar";
     /// // this would be clearer as `eprintln!("foo: {:?}", bar);`
-    /// writeln!(&mut io::stderr(), "foo: {:?}", bar).unwrap();
+    /// writeln!(&mut std::io::stderr(), "foo: {:?}", bar).unwrap();
     /// ```
     pub EXPLICIT_WRITE,
     complexity,

clippy_lints/src/format.rs

@@ -26,8 +26,9 @@ declare_clippy_lint! {
     ///
     /// **Examples:**
     /// ```rust
-    /// format!("foo")
-    /// format!("{}", foo)
+    /// # let foo = "foo";
+    /// format!("foo");
+    /// format!("{}", foo);
     /// ```
     pub USELESS_FORMAT,
     complexity,

clippy_lints/src/functions.rs

@@ -23,8 +23,9 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
+    /// # struct Color;
     /// fn foo(x: u32, y: u32, name: &str, c: Color, w: f32, h: f32, a: f32, b: f32) {
-    ///     ..
+    ///     // ..
     /// }
     /// ```
     pub TOO_MANY_ARGUMENTS,

clippy_lints/src/identity_op.rs

@@ -17,7 +17,8 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
-    /// x / 1 + 0 * 1 - 0 | 0
+    /// # let x = 1;
+    /// x / 1 + 0 * 1 - 0 | 0;
     /// ```
     pub IDENTITY_OP,
     complexity,

clippy_lints/src/int_plus_one.rs

@@ -17,13 +17,17 @@ declare_clippy_lint! {
     ///
     /// **Example:**
     /// ```rust
-    /// x >= y + 1
+    /// # let x = 1;
+    /// # let y = 1;
+    /// if x >= y + 1 {}
     /// ```
     ///
-    /// Could be written:
+    /// Could be written as:
     ///
     /// ```rust
-    /// x > y
+    /// # let x = 1;
+    /// # let y = 1;
+    /// if x > y {}
     /// ```
     pub INT_PLUS_ONE,
     complexity,