src/tools/clippy/tests/ui/vec_init_then_push.rs

   1 #![allow(unused_variables)]
   2 #![warn(clippy::vec_init_then_push)]
   3 //@no-rustfix
   4 fn main() {
   5     let mut def_err: Vec<u32> = Default::default();
   6     //~^ ERROR: calls to `push` immediately after creation
   7     //~| NOTE: `-D clippy::vec-init-then-push` implied by `-D warnings`
   8     def_err.push(0);
   9
  10     let mut new_err = Vec::<u32>::new();
  11     //~^ ERROR: calls to `push` immediately after creation
  12     new_err.push(1);
  13
  14     let mut cap_err = Vec::with_capacity(2);
  15     //~^ ERROR: calls to `push` immediately after creation
  16     cap_err.push(0);
  17     cap_err.push(1);
  18     cap_err.push(2);
  19     if true {
  20         // don't include this one
  21         cap_err.push(3);
  22     }
  23
  24     let mut cap_ok = Vec::with_capacity(10);
  25     cap_ok.push(0);
  26
  27     new_err = Vec::new();
  28     //~^ ERROR: calls to `push` immediately after creation
  29     new_err.push(0);
  30
  31     let mut vec = Vec::new();
  32     // control flow at block final expression
  33     if true {
  34         // no lint
  35         vec.push(1);
  36     }
  37
  38     let mut vec = Vec::with_capacity(5);
  39     vec.push(1);
  40     vec.push(2);
  41     vec.push(3);
  42     vec.push(4);
  43 }
  44
  45 pub fn no_lint() -> Vec<i32> {
  46     let mut p = Some(1);
  47     let mut vec = Vec::new();
  48     loop {
  49         match p {
  50             None => return vec,
  51             Some(i) => {
  52                 vec.push(i);
  53                 p = None;
  54             },
  55         }
  56     }
  57 }
  58
  59 fn _from_iter(items: impl Iterator<Item = u32>) -> Vec<u32> {
  60     let mut v = Vec::new();
  61     v.push(0);
  62     v.push(1);
  63     v.extend(items);
  64     v
  65 }
  66
  67 fn _cond_push(x: bool) -> Vec<u32> {
  68     let mut v = Vec::new();
  69     v.push(0);
  70     if x {
  71         v.push(1);
  72     }
  73     v.push(2);
  74     v
  75 }
  76
  77 fn _push_then_edit(x: u32) -> Vec<u32> {
  78     let mut v = Vec::new();
  79     //~^ ERROR: calls to `push` immediately after creation
  80     v.push(x);
  81     v.push(1);
  82     v[0] = v[1] + 5;
  83     v
  84 }
  85
  86 fn _cond_push_with_large_start(x: bool) -> Vec<u32> {
  87     let mut v = Vec::new();
  88     //~^ ERROR: calls to `push` immediately after creation
  89     v.push(0);
  90     v.push(1);
  91     v.push(0);
  92     v.push(1);
  93     v.push(0);
  94     v.push(0);
  95     v.push(1);
  96     v.push(0);
  97     if x {
  98         v.push(1);
  99     }
 100
 101     let mut v2 = Vec::new();
 102     //~^ ERROR: calls to `push` immediately after creation
 103     v2.push(0);
 104     v2.push(1);
 105     v2.push(0);
 106     v2.push(1);
 107     v2.push(0);
 108     v2.push(0);
 109     v2.push(1);
 110     v2.push(0);
 111     v2.extend(&v);
 112
 113     v2
 114 }
 115
 116 fn f() {
 117     let mut v = Vec::new();
 118     //~^ ERROR: calls to `push` immediately after creation
 119     v.push((0i32, 0i32));
 120     let y = v[0].0.abs();
 121 }