#![deny(clippy::useless_conversion)] use std::convert::{TryFrom, TryInto}; fn test_generic<T: Copy>(val: T) -> T { let _ = T::try_from(val).unwrap(); val.try_into().unwrap() } fn test_generic2<T: Copy + Into<i32> + Into<U>, U: From<T>>(val: T) { // ok let _: i32 = val.try_into().unwrap(); let _: U = val.try_into().unwrap(); let _ = U::try_from(val).unwrap(); } fn main() { test_generic(10i32); test_generic2::<i32, i32>(10i32); let _: String = "foo".try_into().unwrap(); let _: String = TryFrom::try_from("foo").unwrap(); let _ = String::try_from("foo").unwrap(); #[allow(clippy::useless_conversion)] { let _ = String::try_from("foo").unwrap(); let _: String = "foo".try_into().unwrap(); } let _: String = "foo".to_string().try_into().unwrap(); let _: String = TryFrom::try_from("foo".to_string()).unwrap(); let _ = String::try_from("foo".to_string()).unwrap(); let _ = String::try_from(format!("A: {:04}", 123)).unwrap(); let _: String = format!("Hello {}", "world").try_into().unwrap(); let _: String = "".to_owned().try_into().unwrap(); let _: String = match String::from("_").try_into() { Ok(a) => a, Err(_) => "".into(), }; // FIXME this is a false negative #[allow(clippy::cmp_owned)] if String::from("a") == TryInto::<String>::try_into(String::from("a")).unwrap() {} }