src/tools/clippy/tests/ui/std_instead_of_core.fixed

   1 //@aux-build:proc_macro_derive.rs
   2 #![warn(clippy::std_instead_of_core)]
   3 #![allow(unused_imports)]
   4
   5 extern crate alloc;
   6
   7 #[macro_use]
   8 extern crate proc_macro_derive;
   9
  10 #[warn(clippy::std_instead_of_core)]
  11 fn std_instead_of_core() {
  12     // Regular import
  13     use core::hash::Hasher;
  14     //~^ ERROR: used import from `std` instead of `core`
  15     // Absolute path
  16     use ::core::hash::Hash;
  17     //~^ ERROR: used import from `std` instead of `core`
  18     // Don't lint on `env` macro
  19     use std::env;
  20
  21     // Multiple imports
  22     use core::fmt::{Debug, Result};
  23     //~^ ERROR: used import from `std` instead of `core`
  24
  25     // Function calls
  26     let ptr = core::ptr::null::<u32>();
  27     //~^ ERROR: used import from `std` instead of `core`
  28     let ptr_mut = ::core::ptr::null_mut::<usize>();
  29     //~^ ERROR: used import from `std` instead of `core`
  30
  31     // Types
  32     let cell = core::cell::Cell::new(8u32);
  33     //~^ ERROR: used import from `std` instead of `core`
  34     let cell_absolute = ::core::cell::Cell::new(8u32);
  35     //~^ ERROR: used import from `std` instead of `core`
  36
  37     let _ = std::env!("PATH");
  38
  39     // do not lint until `error_in_core` is stable
  40     use std::error::Error;
  41
  42     // lint items re-exported from private modules, `core::iter::traits::iterator::Iterator`
  43     use core::iter::Iterator;
  44     //~^ ERROR: used import from `std` instead of `core`
  45 }
  46
  47 #[warn(clippy::std_instead_of_alloc)]
  48 fn std_instead_of_alloc() {
  49     // Only lint once.
  50     use alloc::vec;
  51     //~^ ERROR: used import from `std` instead of `alloc`
  52     use alloc::vec::Vec;
  53     //~^ ERROR: used import from `std` instead of `alloc`
  54 }
  55
  56 #[warn(clippy::alloc_instead_of_core)]
  57 fn alloc_instead_of_core() {
  58     use core::slice::from_ref;
  59     //~^ ERROR: used import from `alloc` instead of `core`
  60 }
  61
  62 mod std_in_proc_macro_derive {
  63     #[warn(clippy::alloc_instead_of_core)]
  64     #[allow(unused)]
  65     #[derive(ImplStructWithStdDisplay)]
  66     struct B {}
  67 }
  68
  69 fn main() {
  70     std_instead_of_core();
  71     std_instead_of_alloc();
  72     alloc_instead_of_core();
  73 }