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#![warn(clippy::missing_const_for_fn)]
#![allow(incomplete_features, clippy::let_and_return)]
use std::mem::transmute;
struct Game {
guess: i32,
}
impl Game {
// Could be const
pub fn new() -> Self {
Self { guess: 42 }
}
fn const_generic_params<'a, T, const N: usize>(&self, b: &'a [T; N]) -> &'a [T; N] {
b
}
}
// Could be const
fn one() -> i32 {
1
}
// Could also be const
fn two() -> i32 {
let abc = 2;
abc
}
// Could be const (since Rust 1.39)
fn string() -> String {
String::new()
}
// Could be const
unsafe fn four() -> i32 {
4
}
// Could also be const
fn generic<T>(t: T) -> T {
t
}
fn sub(x: u32) -> usize {
unsafe { transmute(&x) }
}
fn generic_arr<T: Copy>(t: [T; 1]) -> T {
t[0]
}
mod with_drop {
pub struct A;
pub struct B;
impl Drop for A {
fn drop(&mut self) {}
}
impl B {
// This can be const, because `a` is passed by reference
pub fn b(self, a: &A) -> B {
B
}
}
}
#[clippy::msrv = "1.47.0"]
mod const_fn_stabilized_before_msrv {
// This could be const because `u8::is_ascii_digit` is a stable const function in 1.47.
fn const_fn_stabilized_before_msrv(byte: u8) {
byte.is_ascii_digit();
}
}
#[clippy::msrv = "1.45"]
fn msrv_1_45() -> i32 {
45
}
#[clippy::msrv = "1.46"]
fn msrv_1_46() -> i32 {
46
}
// Should not be const
fn main() {}
|
