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#![warn(clippy::needless_pass_by_value)]
#![allow(dead_code)]
#![allow(
clippy::option_option,
clippy::redundant_clone,
clippy::redundant_pattern_matching,
clippy::single_match,
clippy::uninlined_format_args
)]
//@no-rustfix
use std::borrow::Borrow;
use std::collections::HashSet;
use std::convert::AsRef;
use std::mem::MaybeUninit;
// `v` should be warned
// `w`, `x` and `y` are allowed (moved or mutated)
fn foo<T: Default>(v: Vec<T>, w: Vec<T>, mut x: Vec<T>, y: Vec<T>) -> Vec<T> {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
//~| NOTE: `-D clippy::needless-pass-by-value` implied by `-D warnings`
assert_eq!(v.len(), 42);
consume(w);
x.push(T::default());
y
}
fn consume<T>(_: T) {}
struct Wrapper(String);
fn bar(x: String, y: Wrapper) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
assert_eq!(x.len(), 42);
assert_eq!(y.0.len(), 42);
}
// V implements `Borrow<V>`, but should be warned correctly
fn test_borrow_trait<T: Borrow<str>, U: AsRef<str>, V>(t: T, u: U, v: V) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
println!("{}", t.borrow());
println!("{}", u.as_ref());
consume(&v);
}
// ok
fn test_fn<F: Fn(i32) -> i32>(f: F) {
f(1);
}
// x should be warned, but y is ok
fn test_match(x: Option<Option<String>>, y: Option<Option<String>>) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
match x {
Some(Some(_)) => 1, // not moved
_ => 0,
};
match y {
Some(Some(s)) => consume(s), // moved
_ => (),
};
}
// x and y should be warned, but z is ok
fn test_destructure(x: Wrapper, y: Wrapper, z: Wrapper) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
let Wrapper(s) = z; // moved
let Wrapper(ref t) = y; // not moved
let Wrapper(_) = y; // still not moved
assert_eq!(x.0.len(), s.len());
println!("{}", t);
}
trait Foo {}
// `S: Serialize` is allowed to be passed by value, since a caller can pass `&S` instead
trait Serialize {}
impl<'a, T> Serialize for &'a T where T: Serialize {}
impl Serialize for i32 {}
fn test_blanket_ref<T: Foo, S: Serialize>(_foo: T, _serializable: S) {}
//~^ ERROR: this argument is passed by value, but not consumed in the function body
fn issue_2114(s: String, t: String, u: Vec<i32>, v: Vec<i32>) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
s.capacity();
let _ = t.clone();
u.capacity();
let _ = v.clone();
}
struct S<T, U>(T, U);
impl<T: Serialize, U> S<T, U> {
fn foo(
self,
// taking `self` by value is always allowed
s: String,
//~^ ERROR: this argument is passed by value, but not consumed in the function bod
t: String,
//~^ ERROR: this argument is passed by value, but not consumed in the function bod
) -> usize {
s.len() + t.capacity()
}
fn bar(_t: T, // Ok, since `&T: Serialize` too
) {
}
fn baz(&self, _u: U, _s: Self) {}
//~^ ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
}
trait FalsePositive {
fn visit_str(s: &str);
fn visit_string(s: String) {
Self::visit_str(&s);
}
}
// shouldn't warn on extern funcs
extern "C" fn ext(x: MaybeUninit<usize>) -> usize {
unsafe { x.assume_init() }
}
// exempt RangeArgument
fn range<T: ::std::ops::RangeBounds<usize>>(range: T) {
let _ = range.start_bound();
}
struct CopyWrapper(u32);
fn bar_copy(x: u32, y: CopyWrapper) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
assert_eq!(x, 42);
assert_eq!(y.0, 42);
}
// x and y should be warned, but z is ok
fn test_destructure_copy(x: CopyWrapper, y: CopyWrapper, z: CopyWrapper) {
//~^ ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
//~| ERROR: this argument is passed by value, but not consumed in the function body
let CopyWrapper(s) = z; // moved
let CopyWrapper(ref t) = y; // not moved
let CopyWrapper(_) = y; // still not moved
assert_eq!(x.0, s);
println!("{}", t);
}
// The following 3 lines should not cause an ICE. See #2831
trait Bar<'a, A> {}
impl<'b, T> Bar<'b, T> for T {}
fn some_fun<'b, S: Bar<'b, ()>>(_item: S) {}
//~^ ERROR: this argument is passed by value, but not consumed in the function body
// Also this should not cause an ICE. See #2831
trait Club<'a, A> {}
impl<T> Club<'static, T> for T {}
fn more_fun(_item: impl Club<'static, i32>) {}
//~^ ERROR: this argument is passed by value, but not consumed in the function body
fn is_sync<T>(_: T)
where
T: Sync,
{
}
fn main() {
// This should not cause an ICE either
// https://github.com/rust-lang/rust-clippy/issues/3144
is_sync(HashSet::<usize>::new());
}
|
