54 lines
1.3 KiB
Rust
54 lines
1.3 KiB
Rust
// Test several functions can be used for constants
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// 1. Vec::new()
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// 2. String::new()
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// 3. BTreeMap::new()
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// 4. BTreeSet::new()
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#[allow(dead_code)]
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pub const MY_VEC: Vec<usize> = Vec::new();
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#[allow(dead_code)]
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pub const MY_STRING: String = String::new();
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// FIXME remove this struct once we put `K: ?const Ord` on BTreeMap::new.
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#[derive(PartialEq, Eq, PartialOrd)]
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pub struct MyType;
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impl const Ord for MyType {
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fn cmp(&self, _: &Self) -> Ordering {
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Ordering::Equal
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}
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fn max(self, _: Self) -> Self {
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Self
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}
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fn min(self, _: Self) -> Self {
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Self
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}
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fn clamp(self, _: Self, _: Self) -> Self {
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Self
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}
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}
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use core::cmp::Ordering;
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use std::collections::{BTreeMap, BTreeSet};
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pub const MY_BTREEMAP: BTreeMap<MyType, MyType> = BTreeMap::new();
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pub const MAP: &'static BTreeMap<MyType, MyType> = &MY_BTREEMAP;
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pub const MAP_LEN: usize = MAP.len();
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pub const MAP_IS_EMPTY: bool = MAP.is_empty();
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pub const MY_BTREESET: BTreeSet<MyType> = BTreeSet::new();
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pub const SET: &'static BTreeSet<MyType> = &MY_BTREESET;
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pub const SET_LEN: usize = SET.len();
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pub const SET_IS_EMPTY: bool = SET.is_empty();
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#[test]
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fn test_const() {
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assert_eq!(MAP_LEN, 0);
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assert_eq!(SET_LEN, 0);
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assert!(MAP_IS_EMPTY && SET_IS_EMPTY)
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}
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