Implement Hash for tuples of up to arity 12. Also change the style to be consistent with core::tuple #16033
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… be consistent with core::tuple
| impl_hash_tuple!(A B C D E F G H I) | ||
| impl_hash_tuple!(A B C D E F G H I J) | ||
| impl_hash_tuple!(A B C D E F G H I J K) | ||
| impl_hash_tuple!(A B C D E F G H I J K L) |
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Why move from the one line invocation to 12 lines of invocations?
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Maybe this is really silly, but with one line invocation and a recursive macro it ends up coming out like:
impl Trait for (A, B, C, D)
impl Trait for (B, C, D)
impl Trait for (C, D)
impl Trait for (D,)
I want it to come out
impl Trait for (A,)
impl Trait for (A, B)
impl Trait for (A, B, C)
impl Trait for (A, B, C, D)
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In that case, could the recursive macro invocation be placed first?
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That will help a bit, but it will still expand to
impl Trait for (D,)
impl Trait for (C, D)
impl Trait for (B, C, D)
impl Trait for (A, B, C, D)
I was mostly doing it so that the implementation for a 1-tuple would use "A", for a 2-tuple would use "A, B", for a 3-tuple would use "A, B, C", etc. Maybe this is too minor to worry about.
bors
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Jul 29, 2014
Previously the implementation of Hash was limited to tuples of up to arity 8. This increases it to tuples of up to arity 12.
Also, the implementation macro for `Hash` used to expand to something like this:
impl Hash for (a7,)
impl Hash for (a6, a7)
impl Hash for (a5, a6, a7)
...
This style is inconsistent with the implementations in core::tuple, which look like this:
impl Trait for (A,)
impl Trait for (A, B)
impl Trait for (A, B, C)
...
This is perhaps a minor point, but it does mean the documentation pages are inconsistent. Compare the tuple implementations in the documentation for [Hash](http://static.rust-lang.org/doc/master/std/hash/trait.Hash.html) and [PartialOrd](http://static.rust-lang.org/doc/master/core/cmp/trait.PartialOrd.html)
This changes the Hash implementation to be consistent with `core::tuple`.
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Previously the implementation of Hash was limited to tuples of up to arity 8. This increases it to tuples of up to arity 12.
Also, the implementation macro for
Hashused to expand to something like this:This style is inconsistent with the implementations in core::tuple, which look like this:
This is perhaps a minor point, but it does mean the documentation pages are inconsistent. Compare the tuple implementations in the documentation for Hash and PartialOrd
This changes the Hash implementation to be consistent with
core::tuple.