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	 416399dc10
			
		
	
	
		416399dc10
		
	
	
	
	
		
			
			`Decoder` has two impls: - opaque: this impl is already partly infallible, i.e. in some places it currently panics on failure (e.g. if the input is too short, or on a bad `Result` discriminant), and in some places it returns an error (e.g. on a bad `Option` discriminant). The number of places where either happens is surprisingly small, just because the binary representation has very little redundancy and a lot of input reading can occur even on malformed data. - json: this impl is fully fallible, but it's only used (a) for the `.rlink` file production, and there's a `FIXME` comment suggesting it should change to a binary format, and (b) in a few tests in non-fundamental ways. Indeed #85993 is open to remove it entirely. And the top-level places in the compiler that call into decoding just abort on error anyway. So the fallibility is providing little value, and getting rid of it leads to some non-trivial performance improvements. Much of this commit is pretty boring and mechanical. Some notes about a few interesting parts: - The commit removes `Decoder::{Error,error}`. - `InternIteratorElement::intern_with`: the impl for `T` now has the same optimization for small counts that the impl for `Result<T, E>` has, because it's now much hotter. - Decodable impls for SmallVec, LinkedList, VecDeque now all use `collect`, which is nice; the one for `Vec` uses unsafe code, because that gave better perf on some benchmarks.
		
			
				
	
	
		
			277 lines
		
	
	
		
			5.5 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			277 lines
		
	
	
		
			5.5 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| #![allow(rustc::internal)]
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| 
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| use rustc_macros::{Decodable, Encodable};
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| use rustc_serialize::opaque::{Decoder, Encoder};
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| use rustc_serialize::{Decodable, Encodable};
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| use std::fmt::Debug;
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| 
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| #[derive(PartialEq, Clone, Debug, Encodable, Decodable)]
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| struct Struct {
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|     a: (),
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|     b: u8,
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|     c: u16,
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|     d: u32,
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|     e: u64,
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|     f: usize,
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| 
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|     g: i8,
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|     h: i16,
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|     i: i32,
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|     j: i64,
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|     k: isize,
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| 
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|     l: char,
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|     m: String,
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|     n: f32,
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|     o: f64,
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|     p: bool,
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|     q: Option<u32>,
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| }
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| 
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| fn check_round_trip<T: Encodable<Encoder> + for<'a> Decodable<Decoder<'a>> + PartialEq + Debug>(
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|     values: Vec<T>,
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| ) {
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|     let mut encoder = Encoder::new(Vec::new());
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| 
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|     for value in &values {
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|         Encodable::encode(value, &mut encoder).unwrap();
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|     }
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| 
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|     let data = encoder.into_inner();
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|     let mut decoder = Decoder::new(&data[..], 0);
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| 
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|     for value in values {
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|         let decoded = Decodable::decode(&mut decoder);
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|         assert_eq!(value, decoded);
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|     }
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| }
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| 
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| #[test]
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| fn test_unit() {
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|     check_round_trip(vec![(), (), (), ()]);
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| }
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| 
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| #[test]
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| fn test_u8() {
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|     let mut vec = vec![];
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|     for i in u8::MIN..u8::MAX {
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|         vec.push(i);
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|     }
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|     check_round_trip(vec);
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| }
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| 
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| #[test]
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| fn test_u16() {
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|     for i in u16::MIN..u16::MAX {
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|         check_round_trip(vec![1, 2, 3, i, i, i]);
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|     }
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| }
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| 
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| #[test]
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| fn test_u32() {
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|     check_round_trip(vec![1, 2, 3, u32::MIN, 0, 1, u32::MAX, 2, 1]);
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| }
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| 
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| #[test]
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| fn test_u64() {
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|     check_round_trip(vec![1, 2, 3, u64::MIN, 0, 1, u64::MAX, 2, 1]);
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| }
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| 
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| #[test]
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| fn test_usize() {
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|     check_round_trip(vec![1, 2, 3, usize::MIN, 0, 1, usize::MAX, 2, 1]);
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| }
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| 
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| #[test]
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| fn test_i8() {
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|     let mut vec = vec![];
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|     for i in i8::MIN..i8::MAX {
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|         vec.push(i);
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|     }
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|     check_round_trip(vec);
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| }
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| 
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| #[test]
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| fn test_i16() {
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|     for i in i16::MIN..i16::MAX {
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|         check_round_trip(vec![-1, 2, -3, i, i, i, 2]);
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|     }
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| }
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| 
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| #[test]
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| fn test_i32() {
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|     check_round_trip(vec![-1, 2, -3, i32::MIN, 0, 1, i32::MAX, 2, 1]);
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| }
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| 
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| #[test]
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| fn test_i64() {
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|     check_round_trip(vec![-1, 2, -3, i64::MIN, 0, 1, i64::MAX, 2, 1]);
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| }
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| 
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| #[test]
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| fn test_isize() {
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|     check_round_trip(vec![-1, 2, -3, isize::MIN, 0, 1, isize::MAX, 2, 1]);
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| }
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| 
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| #[test]
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| fn test_bool() {
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|     check_round_trip(vec![false, true, true, false, false]);
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| }
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| 
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| #[test]
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| fn test_f32() {
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|     let mut vec = vec![];
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|     for i in -100..100 {
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|         vec.push((i as f32) / 3.0);
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|     }
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|     check_round_trip(vec);
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| }
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| 
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| #[test]
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| fn test_f64() {
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|     let mut vec = vec![];
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|     for i in -100..100 {
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|         vec.push((i as f64) / 3.0);
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|     }
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|     check_round_trip(vec);
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| }
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| 
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| #[test]
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| fn test_char() {
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|     let vec = vec!['a', 'b', 'c', 'd', 'A', 'X', ' ', '#', 'Ö', 'Ä', 'µ', '€'];
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|     check_round_trip(vec);
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| }
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| 
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| #[test]
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| fn test_string() {
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|     let vec = vec![
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|         "abcbuÖeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
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|         "abcbuÖganeiovÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
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|         "abcbuÖganeiovÄnameÜavmpßvmea€µsbpapmaebn".to_string(),
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|         "abcbuÖganeiovÄnameÜavmpßvmeabpnvapeapmaebn".to_string(),
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|         "abcbuÖganeiÄnameÜavmpßvmea€µsbpnvapeapmaebn".to_string(),
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|         "abcbuÖganeiovÄnameÜavmpßvmea€µsbpmaebn".to_string(),
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|         "abcbuÖganeiovÄnameÜavmpßvmea€µnvapeapmaebn".to_string(),
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|     ];
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| 
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|     check_round_trip(vec);
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| }
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| 
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| #[test]
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| fn test_option() {
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|     check_round_trip(vec![Some(-1i8)]);
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|     check_round_trip(vec![Some(-2i16)]);
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|     check_round_trip(vec![Some(-3i32)]);
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|     check_round_trip(vec![Some(-4i64)]);
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|     check_round_trip(vec![Some(-5isize)]);
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| 
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|     let none_i8: Option<i8> = None;
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|     check_round_trip(vec![none_i8]);
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| 
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|     let none_i16: Option<i16> = None;
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|     check_round_trip(vec![none_i16]);
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| 
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|     let none_i32: Option<i32> = None;
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|     check_round_trip(vec![none_i32]);
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| 
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|     let none_i64: Option<i64> = None;
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|     check_round_trip(vec![none_i64]);
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| 
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|     let none_isize: Option<isize> = None;
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|     check_round_trip(vec![none_isize]);
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| }
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| 
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| #[test]
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| fn test_struct() {
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|     check_round_trip(vec![Struct {
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|         a: (),
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|         b: 10,
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|         c: 11,
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|         d: 12,
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|         e: 13,
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|         f: 14,
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| 
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|         g: 15,
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|         h: 16,
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|         i: 17,
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|         j: 18,
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|         k: 19,
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| 
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|         l: 'x',
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|         m: "abc".to_string(),
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|         n: 20.5,
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|         o: 21.5,
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|         p: false,
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|         q: None,
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|     }]);
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| 
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|     check_round_trip(vec![Struct {
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|         a: (),
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|         b: 101,
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|         c: 111,
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|         d: 121,
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|         e: 131,
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|         f: 141,
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| 
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|         g: -15,
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|         h: -16,
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|         i: -17,
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|         j: -18,
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|         k: -19,
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| 
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|         l: 'y',
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|         m: "def".to_string(),
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|         n: -20.5,
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|         o: -21.5,
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|         p: true,
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|         q: Some(1234567),
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|     }]);
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| }
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| 
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| #[derive(PartialEq, Clone, Debug, Encodable, Decodable)]
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| enum Enum {
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|     Variant1,
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|     Variant2(usize, f32),
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|     Variant3 { a: i32, b: char, c: bool },
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| }
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| 
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| #[test]
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| fn test_enum() {
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|     check_round_trip(vec![
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|         Enum::Variant1,
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|         Enum::Variant2(1, 2.5),
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|         Enum::Variant3 { a: 3, b: 'b', c: false },
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|         Enum::Variant3 { a: -4, b: 'f', c: true },
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|     ]);
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| }
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| 
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| #[test]
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| fn test_sequence() {
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|     let mut vec = vec![];
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|     for i in -100i64..100i64 {
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|         vec.push(i * 100000);
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|     }
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| 
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|     check_round_trip(vec![vec]);
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| }
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| 
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| #[test]
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| fn test_hash_map() {
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|     use std::collections::HashMap;
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|     let mut map = HashMap::new();
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|     for i in -100i64..100i64 {
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|         map.insert(i * 100000, i * 10000);
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|     }
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| 
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|     check_round_trip(vec![map]);
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| }
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| 
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| #[test]
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| fn test_tuples() {
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|     check_round_trip(vec![('x', (), false, 0.5f32)]);
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|     check_round_trip(vec![(9i8, 10u16, 1.5f64)]);
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|     check_round_trip(vec![(-12i16, 11u8, 12usize)]);
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|     check_round_trip(vec![(1234567isize, 100000000000000u64, 99999999999999i64)]);
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|     check_round_trip(vec![(String::new(), "some string".to_string())]);
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| }
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