48 lines
1.3 KiB
Rust
48 lines
1.3 KiB
Rust
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#![allow(print_literal)]
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#![warn(useless_format)]
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struct Foo(pub String);
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macro_rules! foo {
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($($t:tt)*) => (Foo(format!($($t)*)))
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}
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fn main() {
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format!("foo");
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format!("{}", "foo");
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format!("{:?}", "foo"); // don't warn about debug
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format!("{:8}", "foo");
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format!("{:+}", "foo"); // warn when the format makes no difference
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format!("{:<}", "foo"); // warn when the format makes no difference
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format!("foo {}", "bar");
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format!("{} bar", "foo");
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let arg: String = "".to_owned();
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format!("{}", arg);
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format!("{:?}", arg); // don't warn about debug
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format!("{:8}", arg);
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format!("{:+}", arg); // warn when the format makes no difference
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format!("{:<}", arg); // warn when the format makes no difference
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format!("foo {}", arg);
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format!("{} bar", arg);
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// we don’t want to warn for non-string args, see #697
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format!("{}", 42);
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format!("{:?}", 42);
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format!("{:+}", 42);
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format!("foo {}", 42);
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format!("{} bar", 42);
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// we only want to warn about `format!` itself
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println!("foo");
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println!("{}", "foo");
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println!("foo {}", "foo");
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println!("{}", 42);
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println!("foo {}", 42);
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// A format! inside a macro should not trigger a warning
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foo!("should not warn");
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}
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