rust/tests/compile-fail/len_zero.rs
2016-03-18 14:06:39 +01:00

130 lines
2.9 KiB
Rust

#![feature(plugin)]
#![plugin(clippy)]
struct One;
#[deny(len_without_is_empty)]
impl One {
fn len(self: &Self) -> isize { //~ERROR item `One` has a `.len(_: &Self)`
1
}
}
#[deny(len_without_is_empty)]
trait TraitsToo {
fn len(self: &Self) -> isize; //~ERROR trait `TraitsToo` has a `.len(_:
}
impl TraitsToo for One {
fn len(self: &Self) -> isize {
0
}
}
struct HasIsEmpty;
#[deny(len_without_is_empty)]
impl HasIsEmpty {
fn len(self: &Self) -> isize {
1
}
fn is_empty(self: &Self) -> bool {
false
}
}
struct Wither;
#[deny(len_without_is_empty)]
trait WithIsEmpty {
fn len(self: &Self) -> isize;
fn is_empty(self: &Self) -> bool;
}
impl WithIsEmpty for Wither {
fn len(self: &Self) -> isize {
1
}
fn is_empty(self: &Self) -> bool {
false
}
}
struct HasWrongIsEmpty;
#[deny(len_without_is_empty)]
impl HasWrongIsEmpty {
fn len(self: &Self) -> isize { //~ERROR item `HasWrongIsEmpty` has a `.len(_: &Self)`
1
}
#[allow(dead_code, unused)]
fn is_empty(self: &Self, x : u32) -> bool {
false
}
}
#[deny(len_zero)]
fn main() {
let x = [1, 2];
if x.len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION x.is_empty()
println!("This should not happen!");
}
if "".len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION "".is_empty()
}
let y = One;
if y.len() == 0 { //no error because One does not have .is_empty()
println!("This should not happen either!");
}
let z : &TraitsToo = &y;
if z.len() > 0 { //no error, because TraitsToo has no .is_empty() method
println!("Nor should this!");
}
let has_is_empty = HasIsEmpty;
if has_is_empty.len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION has_is_empty.is_empty()
println!("Or this!");
}
if has_is_empty.len() != 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION !has_is_empty.is_empty()
println!("Or this!");
}
if has_is_empty.len() > 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION !has_is_empty.is_empty()
println!("Or this!");
}
assert!(!has_is_empty.is_empty());
let with_is_empty: &WithIsEmpty = &Wither;
if with_is_empty.len() == 0 {
//~^ERROR length comparison to zero
//~|HELP consider using `is_empty`
//~|SUGGESTION with_is_empty.is_empty()
println!("Or this!");
}
assert!(!with_is_empty.is_empty());
let has_wrong_is_empty = HasWrongIsEmpty;
if has_wrong_is_empty.len() == 0 { //no error as HasWrongIsEmpty does not have .is_empty()
println!("Or this!");
}
}