More vect (#496)

* Add generic vect method

* Minor version bump

* Style fix

* Fix test

* Improve inferability

Co-authored-by: Michael Abbott <32575566+mcabbott@users.noreply.github.com>

* Improve comment

Co-authored-by: Lyndon White <oxinabox@ucc.asn.au>

* Update comment

* Change comment

* Bump minor version

Co-authored-by: Michael Abbott <32575566+mcabbott@users.noreply.github.com>
Co-authored-by: Lyndon White <oxinabox@ucc.asn.au>

Author: 3 people

Project.toml

@@ -1,6 +1,6 @@
 name = "ChainRules"
 uuid = "082447d4-558c-5d27-93f4-14fc19e9eca2"
-version = "1.6.0"
+version = "1.7.0"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/rulesets/Base/array.jl

@@ -37,6 +37,12 @@ function rrule(
     return Base.vect(X...), vect_pullback
 end
 
+# Data is unmodified, so no need to project.
+function rrule(::typeof(Base.vect), X::Vararg{Any,N}) where {N}
+    vect_pullback(ȳ) = (NoTangent(), ntuple(n -> ȳ[n], N)...)
+    return Base.vect(X...), vect_pullback
+end
+
 #####
 ##### `reshape`
 #####

test/rulesets/Base/array.jl

@@ -32,6 +32,7 @@ end
             atol=1e-6, rtol=1e-6, check_inferred=VERSION>=v"1.6",
         ) # tolerance due to Float32.
         test_rrule(Base.vect, 5.0, randn(3, 3); check_inferred=false)
+        test_rrule(Base.vect, (5.0, 4.0), (y=randn(3),); check_inferred=false)
     end
 end