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			15 lines
		
	
	
		
			358 B
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			15 lines
		
	
	
		
			358 B
		
	
	
	
		
			Rust
		
	
	
	
	
	
| // error-pattern: attempted to define built-in macro more than once
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| 
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| #![feature(rustc_attrs)]
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| 
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| #[rustc_builtin_macro]
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| macro_rules! unknown { () => () } //~ ERROR cannot find a built-in macro with name `unknown`
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| 
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| #[rustc_builtin_macro]
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| macro_rules! line { () => () } //~ NOTE previously defined here
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| 
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| fn main() {
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|     line!();
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|     std::prelude::v1::line!();
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| }
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