rust/tests/compile-fail/methods.rs

50 lines
1.4 KiB
Rust
Executable File

#![feature(plugin)]
#![plugin(clippy)]
#![allow(unused)]
#![deny(clippy, clippy_pedantic)]
use std::ops::Mul;
struct T;
impl T {
fn add(self, other: T) -> T { self } //~ERROR defining a method called `add`
fn drop(&mut self) { } //~ERROR defining a method called `drop`
fn sub(&self, other: T) -> &T { self } // no error, self is a ref
fn div(self) -> T { self } // no error, different #arguments
fn rem(self, other: T) { } // no error, wrong return type
fn into_u32(self) -> u32 { 0 } // fine
fn into_u16(&self) -> u16 { 0 } //~ERROR methods called `into_*` usually take self by value
fn to_something(self) -> u32 { 0 } //~ERROR methods called `to_*` usually take self by reference
}
#[derive(Clone,Copy)]
struct U;
impl U {
fn to_something(self) -> u32 { 0 } // ok because U is Copy
}
impl Mul<T> for T {
type Output = T;
fn mul(self, other: T) -> T { self } // no error, obviously
}
fn main() {
let opt = Some(0);
let _ = opt.unwrap(); //~ERROR used unwrap() on an Option
let res: Result<i32, ()> = Ok(0);
let _ = res.unwrap(); //~ERROR used unwrap() on a Result
let _ = "str".to_string(); //~ERROR `"str".to_owned()` is faster
let v = &"str";
let string = v.to_string(); //~ERROR `(*v).to_owned()` is faster
let _again = string.to_string(); //~ERROR `String.to_string()` is a no-op
}