Crate splitmut [−] [src]
SplitMut - a crate for safely retreiving multiple mutable values within the same collection.
get2_mut, get3_mut and get4_mut return a tuple or 2, 3 or 4 values, each one of them being
one of Ok(&mut V), Err(SplitMutError::NoValue) in case there was no value for the key (i e, when
your usual get_mut would have returned None), or Err(SplitMutError::SameValue) in case the same
value has already been returned earlier in the tuple.
Example
use std::collections::HashMap; use splitmut::{SplitMut, SplitMutError}; // Create a hashmap let mut h = HashMap::new(); h.insert(1, "Hello"); h.insert(2, "world"); // Swap two values easily { let (m1, m2) = h.get2_mut(&1, &2); std::mem::swap(m1.unwrap(), m2.unwrap()); } assert_eq!(h.get(&1), Some(&"world")); assert_eq!(h.get(&2), Some(&"Hello")); // Show error handling let (m0, m1a, m1b) = h.get3_mut(&0, &1, &1); // No value for the key "0" assert_eq!(m0, Err(SplitMutError::NoValue)); // First value for the key "1" is returned successfully assert_eq!(m1a, Ok(&mut "world")); // Second value for the key "1" returns an error assert_eq!(m1b, Err(SplitMutError::SameValue));
Enums
| SplitMutError |
Error returned from get*_mut functions. |
Traits
| SplitMut |
Just add |