| 
						
						
						
					 | 
				
				 | 
				 | 
				
					@ -1,13 +1,13 @@
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					## Advanced Lifetimes
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					## 高级生命周期
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					Back in Chapter 10, we learned how to annotate references with lifetime
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					回到第10章, we learned how to annotate references with lifetime
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					parameters to help Rust understand how the lifetimes of different references
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					relate. We saw how most of the time, Rust will let you elide lifetimes, but
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					every reference has a lifetime. There are three advanced features of lifetimes
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					that we haven't covered though: *lifetime subtyping*, *lifetime
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					bounds*, and *trait object lifetimes*.
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					### Lifetime Subtyping
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					### 生命周期子类型
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					Imagine that we want to write a parser. To do this, we'll have a structure that
 | 
				
			
			
		
	
		
			
				
					 | 
					 | 
				
				 | 
				 | 
				
					holds a reference to the string that we're parsing, and we'll call that struct
 | 
				
			
			
		
	
	
		
			
				
					| 
						
							
								
							
						
						
						
					 | 
				
				 | 
				 | 
				
					
 
 |