83 lines
1.8 KiB
Rust
83 lines
1.8 KiB
Rust
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#![allow(unused)]
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#![warn(
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clippy::all,
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clippy::style,
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clippy::mem_replace_option_with_none,
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clippy::mem_replace_with_default
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)]
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#![feature(lang_items)]
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#![no_std]
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use core::mem;
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use core::panic::PanicInfo;
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#[lang = "eh_personality"]
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extern "C" fn eh_personality() {}
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#[panic_handler]
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fn panic(info: &PanicInfo) -> ! {
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loop {}
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}
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fn replace_option_with_none() {
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let mut an_option = Some(1);
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let _ = mem::replace(&mut an_option, None);
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let an_option = &mut Some(1);
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let _ = mem::replace(an_option, None);
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}
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fn replace_with_default() {
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let mut refstr = "hello";
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let _ = mem::replace(&mut refstr, "");
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let mut slice: &[i32] = &[1, 2, 3];
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let _ = mem::replace(&mut slice, &[]);
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}
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// lint is disabled for primitives because in this case `take`
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// has no clear benefit over `replace` and sometimes is harder to read
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fn dont_lint_primitive() {
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let mut pbool = true;
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let _ = mem::replace(&mut pbool, false);
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let mut pint = 5;
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let _ = mem::replace(&mut pint, 0);
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}
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fn main() {
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replace_option_with_none();
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replace_with_default();
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dont_lint_primitive();
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}
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fn issue9824() {
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struct Foo<'a>(Option<&'a str>);
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impl<'a> core::ops::Deref for Foo<'a> {
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type Target = Option<&'a str>;
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fn deref(&self) -> &Self::Target {
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&self.0
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}
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}
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impl<'a> core::ops::DerefMut for Foo<'a> {
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fn deref_mut(&mut self) -> &mut Self::Target {
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&mut self.0
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}
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}
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struct Bar {
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opt: Option<u8>,
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val: u8,
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}
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let mut f = Foo(Some("foo"));
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let mut b = Bar { opt: Some(1), val: 12 };
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// replace option with none
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let _ = mem::replace(&mut f.0, None);
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let _ = mem::replace(&mut *f, None);
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let _ = mem::replace(&mut b.opt, None);
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// replace with default
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let _ = mem::replace(&mut b.val, u8::default());
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}
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