mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-02 19:53:46 +00:00
38d4ac7cea
Discussion previously happened in https://github.com/rust-lang/rust/pull/43498
59 lines
1.7 KiB
Rust
59 lines
1.7 KiB
Rust
#![allow(clippy::print_literal)]
|
||
#![warn(clippy::useless_format)]
|
||
|
||
struct Foo(pub String);
|
||
|
||
macro_rules! foo {
|
||
($($t:tt)*) => (Foo(format!($($t)*)))
|
||
}
|
||
|
||
fn main() {
|
||
format!("foo");
|
||
|
||
format!("{}", "foo");
|
||
format!("{:?}", "foo"); // don't warn about debug
|
||
format!("{:8}", "foo");
|
||
format!("{:width$}", "foo", width = 8);
|
||
format!("{:+}", "foo"); // warn when the format makes no difference
|
||
format!("{:<}", "foo"); // warn when the format makes no difference
|
||
format!("foo {}", "bar");
|
||
format!("{} bar", "foo");
|
||
|
||
let arg: String = "".to_owned();
|
||
format!("{}", arg);
|
||
format!("{:?}", arg); // don't warn about debug
|
||
format!("{:8}", arg);
|
||
format!("{:width$}", arg, width = 8);
|
||
format!("{:+}", arg); // warn when the format makes no difference
|
||
format!("{:<}", arg); // warn when the format makes no difference
|
||
format!("foo {}", arg);
|
||
format!("{} bar", arg);
|
||
|
||
// we don’t want to warn for non-string args, see #697
|
||
format!("{}", 42);
|
||
format!("{:?}", 42);
|
||
format!("{:+}", 42);
|
||
format!("foo {}", 42);
|
||
format!("{} bar", 42);
|
||
|
||
// we only want to warn about `format!` itself
|
||
println!("foo");
|
||
println!("{}", "foo");
|
||
println!("foo {}", "foo");
|
||
println!("{}", 42);
|
||
println!("foo {}", 42);
|
||
|
||
// A format! inside a macro should not trigger a warning
|
||
foo!("should not warn");
|
||
|
||
// precision on string means slicing without panicking on size:
|
||
format!("{:.1}", "foo"); // could be "foo"[..1]
|
||
format!("{:.10}", "foo"); // could not be "foo"[..10]
|
||
format!("{:.prec$}", "foo", prec = 1);
|
||
format!("{:.prec$}", "foo", prec = 10);
|
||
|
||
format!("{}", 42.to_string());
|
||
let x = std::path::PathBuf::from("/bar/foo/qux");
|
||
format!("{}", x.display().to_string());
|
||
}
|