Paweł Grabarz a81fb7aa7e Add a method iter_combinations on query to iterate over combinations of query results (#1763) ... Related to [discussion on discord](https://discord.com/channels/691052431525675048/742569353878437978/824731187724681289) With const generics, it is now possible to write generic iterator over multiple entities at once. This enables patterns of query iterations like ```rust for [e1, e2, e3] in query.iter_combinations() { // do something with relation of all three entities } ``` The compiler is able to infer the correct iterator for given size of array, so either of those work ```rust for [e1, e2] in query.iter_combinations() { ... } for [e1, e2, e3] in query.iter_combinations() { ... } ``` This feature can be very useful for systems like collision detection. When you ask for permutations of size K of N entities: - if K == N, you get one result of all entities - if K < N, you get all possible subsets of N with size K, without repetition - if K > N, the result set is empty (no permutation of size K exist) Co-authored-by: Carter Anderson <mcanders1@gmail.com>		2021-05-17 23:33:47 +00:00
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macros	Hide Derived SystemParam State Struct From Docs (#1984)	2021-04-22 23:09:59 +00:00
src	Add a method iter_combinations on query to iterate over combinations of query results (#1763)	2021-05-17 23:33:47 +00:00
Cargo.toml	Release 0.5.0 (#1835)	2021-04-06 18:48:48 +00:00