diff --git a/Manifest.toml b/Manifest.toml
index be9bf768..115fa5f5 100644
--- a/Manifest.toml
+++ b/Manifest.toml
@@ -1,8 +1,10 @@
+# This file is machine-generated - editing it directly is not advised
+
 [[AbstractFFTs]]
 deps = ["LinearAlgebra"]
-git-tree-sha1 = "380e36c66edfa099cd90116b24c1ce8cafccac40"
+git-tree-sha1 = "051c95d6836228d120f5f4b984dd5aba1624f716"
 uuid = "621f4979-c628-5d54-868e-fcf4e3e8185c"
-version = "0.4.1"
+version = "0.5.0"
 
 [[AbstractTrees]]
 deps = ["Markdown", "Test"]
@@ -19,12 +21,6 @@ version = "1.0.0"
 [[Base64]]
 uuid = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
 
-[[BinDeps]]
-deps = ["Compat", "Libdl", "SHA", "URIParser"]
-git-tree-sha1 = "12093ca6cdd0ee547c39b1870e0c9c3f154d9ca9"
-uuid = "9e28174c-4ba2-5203-b857-d8d62c4213ee"
-version = "0.8.10"
-
 [[BinaryProvider]]
 deps = ["Libdl", "SHA"]
 git-tree-sha1 = "5b08ed6036d9d3f0ee6369410b830f8873d4024c"
@@ -38,21 +34,21 @@ version = "0.2.0"
 
 [[CUDAapi]]
 deps = ["Libdl", "Logging"]
-git-tree-sha1 = "6eee47385c81ed3b3f716b745697869c712c2df3"
+git-tree-sha1 = "56a813440ac98a1aa64672ab460a1512552211a7"
 uuid = "3895d2a7-ec45-59b8-82bb-cfc6a382f9b3"
-version = "2.0.0"
+version = "2.1.0"
 
 [[CUDAdrv]]
 deps = ["CEnum", "CUDAapi", "Printf"]
-git-tree-sha1 = "0f39fddace3324707469ace7fbcbc7b28d5cf921"
+git-tree-sha1 = "1fce616fa0806c67c133eb1d2f68f0f1a7504665"
 uuid = "c5f51814-7f29-56b8-a69c-e4d8f6be1fde"
-version = "4.0.4"
+version = "5.0.1"
 
 [[CUDAnative]]
 deps = ["Adapt", "CEnum", "CUDAapi", "CUDAdrv", "DataStructures", "InteractiveUtils", "LLVM", "Libdl", "Printf", "TimerOutputs"]
-git-tree-sha1 = "93f6c917ab2a9b5bb54f8f738f4ec1a6693cb716"
+git-tree-sha1 = "6e11d5c2c91fc623952e94c4fb73f9c4db74795a"
 uuid = "be33ccc6-a3ff-5ff2-a52e-74243cff1e17"
-version = "2.5.5"
+version = "2.7.0"
 
 [[CodecZlib]]
 deps = ["BinaryProvider", "Libdl", "TranscodingStreams"]
@@ -62,9 +58,9 @@ version = "0.6.0"
 
 [[ColorTypes]]
 deps = ["FixedPointNumbers", "Random"]
-git-tree-sha1 = "10050a24b09e8e41b951e9976b109871ce98d965"
+git-tree-sha1 = "7b62b728a5f3dd6ee3b23910303ccf27e82fad5e"
 uuid = "3da002f7-5984-5a60-b8a6-cbb66c0b333f"
-version = "0.8.0"
+version = "0.8.1"
 
 [[Colors]]
 deps = ["ColorTypes", "FixedPointNumbers", "InteractiveUtils", "Printf", "Reexport"]
@@ -78,25 +74,13 @@ git-tree-sha1 = "efdaf19ab11c7889334ca247ff4c9f7c322817b0"
 uuid = "bbf7d656-a473-5ed7-a52c-81e309532950"
 version = "0.2.0"
 
-[[Compat]]
-deps = ["Base64", "Dates", "DelimitedFiles", "Distributed", "InteractiveUtils", "LibGit2", "Libdl", "LinearAlgebra", "Markdown", "Mmap", "Pkg", "Printf", "REPL", "Random", "Serialization", "SharedArrays", "Sockets", "SparseArrays", "Statistics", "Test", "UUIDs", "Unicode"]
-git-tree-sha1 = "ed2c4abadf84c53d9e58510b5fc48912c2336fbb"
-uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
-version = "2.2.0"
-
-[[Conda]]
-deps = ["JSON", "VersionParsing"]
-git-tree-sha1 = "9a11d428dcdc425072af4aea19ab1e8c3e01c032"
-uuid = "8f4d0f93-b110-5947-807f-2305c1781a2d"
-version = "1.3.0"
-
 [[CuArrays]]
 deps = ["AbstractFFTs", "Adapt", "CEnum", "CUDAapi", "CUDAdrv", "CUDAnative", "DataStructures", "GPUArrays", "Libdl", "LinearAlgebra", "MacroTools", "NNlib", "Printf", "Random", "Requires", "SparseArrays", "TimerOutputs"]
-git-tree-sha1 = "7e00178b18672ee2cf37244ac2a273b6b0701b04"
+git-tree-sha1 = "5203ed37039c74c5eab31e9fcdc40f23c7e943a3"
 repo-rev = "master"
 repo-url = "https://github.com/JuliaGPU/CuArrays.jl.git"
 uuid = "3a865a2d-5b23-5a0f-bc46-62713ec82fae"
-version = "1.4.7"
+version = "1.6.0"
 
 [[DataAPI]]
 git-tree-sha1 = "674b67f344687a88310213ddfa8a2b3c76cc4252"
@@ -105,9 +89,9 @@ version = "1.1.0"
 
 [[DataStructures]]
 deps = ["InteractiveUtils", "OrderedCollections"]
-git-tree-sha1 = "a1b652fb77ae8ca7ea328fa7ba5aa151036e5c10"
+git-tree-sha1 = "f784254f428fb8fd7ac15982e5862a38a44523d3"
 uuid = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
-version = "0.17.6"
+version = "0.17.7"
 
 [[Dates]]
 deps = ["Printf"]
@@ -118,26 +102,32 @@ deps = ["Mmap"]
 uuid = "8bb1440f-4735-579b-a4ab-409b98df4dab"
 
 [[DiffResults]]
-deps = ["Compat", "StaticArrays"]
-git-tree-sha1 = "34a4a1e8be7bc99bc9c611b895b5baf37a80584c"
+deps = ["StaticArrays"]
+git-tree-sha1 = "da24935df8e0c6cf28de340b958f6aac88eaa0cc"
 uuid = "163ba53b-c6d8-5494-b064-1a9d43ac40c5"
-version = "0.0.4"
+version = "1.0.2"
 
 [[DiffRules]]
 deps = ["NaNMath", "Random", "SpecialFunctions"]
-git-tree-sha1 = "f734b5f6bc9c909027ef99f6d91d5d9e4b111eed"
+git-tree-sha1 = "10dca52cf6d4a62d82528262921daf63b99704a2"
 uuid = "b552c78f-8df3-52c6-915a-8e097449b14b"
-version = "0.1.0"
+version = "1.0.0"
 
 [[Distributed]]
-deps = ["LinearAlgebra", "Random", "Serialization", "Sockets"]
+deps = ["Random", "Serialization", "Sockets"]
 uuid = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 
 [[FFTW]]
-deps = ["AbstractFFTs", "BinaryProvider", "Conda", "Libdl", "LinearAlgebra", "Reexport", "Test"]
-git-tree-sha1 = "6c5b420da0b8c12098048561b8d58f81adea506f"
+deps = ["AbstractFFTs", "FFTW_jll", "IntelOpenMP_jll", "Libdl", "LinearAlgebra", "MKL_jll", "Reexport"]
+git-tree-sha1 = "109d82fa4b00429f9afcce873e9f746f11f018d3"
 uuid = "7a1cc6ca-52ef-59f5-83cd-3a7055c09341"
-version = "1.0.1"
+version = "1.2.0"
+
+[[FFTW_jll]]
+deps = ["Libdl", "Pkg"]
+git-tree-sha1 = "05674f209a6e3387dd103a945b0113eeb64b1a58"
+uuid = "f5851436-0d7a-5f13-b9de-f02708fd171a"
+version = "3.3.9+3"
 
 [[FillArrays]]
 deps = ["LinearAlgebra", "Random", "SparseArrays"]
@@ -152,15 +142,15 @@ version = "0.6.1"
 
 [[ForwardDiff]]
 deps = ["CommonSubexpressions", "DiffResults", "DiffRules", "NaNMath", "Random", "SpecialFunctions", "StaticArrays"]
-git-tree-sha1 = "da46ac97b17793eba44ff366dc6cb70f1238a738"
+git-tree-sha1 = "840700059391d36e2498d89c2e82c08f261f2a2a"
 uuid = "f6369f11-7733-5829-9624-2563aa707210"
-version = "0.10.7"
+version = "0.10.8"
 
 [[GPUArrays]]
 deps = ["AbstractFFTs", "Adapt", "LinearAlgebra", "Printf", "Random", "Serialization"]
-git-tree-sha1 = "a0a3b927b1a06e63fb8b91950cc7df340b7d912c"
+git-tree-sha1 = "e756da6cee76a5f1436a05827fa8fdf3badc577f"
 uuid = "0c68f7d7-f131-5f86-a1c3-88cf8149b2d7"
-version = "2.0.0"
+version = "2.0.1"
 
 [[IRTools]]
 deps = ["InteractiveUtils", "MacroTools", "Test"]
@@ -168,15 +158,15 @@ git-tree-sha1 = "72421971e60917b8cd7737f9577c4f0f87eab306"
 uuid = "7869d1d1-7146-5819-86e3-90919afe41df"
 version = "0.3.0"
 
-[[InteractiveUtils]]
-deps = ["LinearAlgebra", "Markdown"]
-uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
+[[IntelOpenMP_jll]]
+deps = ["Libdl", "Pkg"]
+git-tree-sha1 = "fb8e1c7a5594ba56f9011310790e03b5384998d6"
+uuid = "1d5cc7b8-4909-519e-a0f8-d0f5ad9712d0"
+version = "2018.0.3+0"
 
-[[JSON]]
-deps = ["Dates", "Mmap", "Parsers", "Unicode"]
-git-tree-sha1 = "b34d7cef7b337321e97d22242c3c2b91f476748e"
-uuid = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
-version = "0.21.0"
+[[InteractiveUtils]]
+deps = ["Markdown"]
+uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 
 [[Juno]]
 deps = ["Base64", "Logging", "Media", "Profile", "Test"]
@@ -186,9 +176,9 @@ version = "0.7.2"
 
 [[LLVM]]
 deps = ["CEnum", "Libdl", "Printf", "Unicode"]
-git-tree-sha1 = "74fe444b8b6d1ac01d639b2f9eaf395bcc2e24fc"
+git-tree-sha1 = "1d08d7e4250f452f6cb20e4574daaebfdbee0ff7"
 uuid = "929cbde3-209d-540e-8aea-75f648917ca0"
-version = "1.3.2"
+version = "1.3.3"
 
 [[LibGit2]]
 uuid = "76f85450-5226-5b5a-8eaa-529ad045b433"
@@ -203,11 +193,17 @@ uuid = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 [[Logging]]
 uuid = "56ddb016-857b-54e1-b83d-db4d58db5568"
 
+[[MKL_jll]]
+deps = ["Libdl", "Pkg"]
+git-tree-sha1 = "61069ae718b8ab1e325bbfb4e5268902e7ea08e3"
+uuid = "856f044c-d86e-5d09-b602-aeab76dc8ba7"
+version = "2019.0.117+0"
+
 [[MacroTools]]
-deps = ["Compat", "DataStructures", "Test"]
-git-tree-sha1 = "82921f0e3bde6aebb8e524efc20f4042373c0c06"
+deps = ["DataStructures", "Markdown", "Random"]
+git-tree-sha1 = "e2fc7a55bb2224e203bbd8b59f72b91323233458"
 uuid = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"
-version = "0.5.2"
+version = "0.5.3"
 
 [[Markdown]]
 deps = ["Base64"]
@@ -229,30 +225,30 @@ version = "0.4.3"
 uuid = "a63ad114-7e13-5084-954f-fe012c677804"
 
 [[NNlib]]
-deps = ["Libdl", "LinearAlgebra", "Requires", "Statistics", "TimerOutputs"]
-git-tree-sha1 = "0c667371391fc6bb31f7f12f96a56a17098b3de8"
+deps = ["BinaryProvider", "Libdl", "LinearAlgebra", "Requires", "Statistics"]
+git-tree-sha1 = "135c0de4794d5e214b06f1fb4787af4a72896e61"
 uuid = "872c559c-99b0-510c-b3b7-b6c96a88d5cd"
-version = "0.6.0"
+version = "0.6.2"
 
 [[NaNMath]]
 git-tree-sha1 = "928b8ca9b2791081dc71a51c55347c27c618760f"
 uuid = "77ba4419-2d1f-58cd-9bb1-8ffee604a2e3"
 version = "0.3.3"
 
+[[OpenSpecFun_jll]]
+deps = ["Libdl", "Pkg"]
+git-tree-sha1 = "65f672edebf3f4e613ddf37db9dcbd7a407e5e90"
+uuid = "efe28fd5-8261-553b-a9e1-b2916fc3738e"
+version = "0.5.3+1"
+
 [[OrderedCollections]]
 deps = ["Random", "Serialization", "Test"]
 git-tree-sha1 = "c4c13474d23c60d20a67b217f1d7f22a40edf8f1"
 uuid = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
 version = "1.1.0"
 
-[[Parsers]]
-deps = ["Dates", "Test"]
-git-tree-sha1 = "0139ba59ce9bc680e2925aec5b7db79065d60556"
-uuid = "69de0a69-1ddd-5017-9359-2bf0b02dc9f0"
-version = "0.3.10"
-
 [[Pkg]]
-deps = ["Dates", "LibGit2", "Markdown", "Printf", "REPL", "Random", "SHA", "UUIDs"]
+deps = ["Dates", "LibGit2", "Libdl", "Logging", "Markdown", "Printf", "REPL", "Random", "SHA", "UUIDs"]
 uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 
 [[Printf]]
@@ -278,10 +274,10 @@ uuid = "189a3867-3050-52da-a836-e630ba90ab69"
 version = "0.2.0"
 
 [[Requires]]
-deps = ["Test"]
-git-tree-sha1 = "f6fbf4ba64d295e146e49e021207993b6b48c7d1"
+deps = ["UUIDs"]
+git-tree-sha1 = "999513b7dea8ac17359ed50ae8ea089e4464e35e"
 uuid = "ae029012-a4dd-5104-9daa-d747884805df"
-version = "0.5.2"
+version = "1.0.0"
 
 [[SHA]]
 uuid = "ea8e919c-243c-51af-8825-aaa63cd721ce"
@@ -289,10 +285,6 @@ uuid = "ea8e919c-243c-51af-8825-aaa63cd721ce"
 [[Serialization]]
 uuid = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
 
-[[SharedArrays]]
-deps = ["Distributed", "Mmap", "Random", "Serialization"]
-uuid = "1a1011a3-84de-559e-8e89-a11a2f7dc383"
-
 [[Sockets]]
 uuid = "6462fe0b-24de-5631-8697-dd941f90decc"
 
@@ -307,10 +299,10 @@ deps = ["LinearAlgebra", "Random"]
 uuid = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 
 [[SpecialFunctions]]
-deps = ["BinDeps", "BinaryProvider", "Libdl"]
-git-tree-sha1 = "3bdd374b6fd78faf0119b8c5d538788dbf910c6e"
+deps = ["OpenSpecFun_jll"]
+git-tree-sha1 = "268052ee908b2c086cc0011f528694f02f3e2408"
 uuid = "276daf66-3868-5448-9aa4-cd146d93841b"
-version = "0.8.0"
+version = "0.9.0"
 
 [[StaticArrays]]
 deps = ["LinearAlgebra", "Random", "Statistics"]
@@ -344,25 +336,13 @@ git-tree-sha1 = "7c53c35547de1c5b9d46a4797cf6d8253807108c"
 uuid = "3bb67fe8-82b1-5028-8e26-92a6c54297fa"
 version = "0.9.5"
 
-[[URIParser]]
-deps = ["Test", "Unicode"]
-git-tree-sha1 = "6ddf8244220dfda2f17539fa8c9de20d6c575b69"
-uuid = "30578b45-9adc-5946-b283-645ec420af67"
-version = "0.4.0"
-
 [[UUIDs]]
-deps = ["Random"]
+deps = ["Random", "SHA"]
 uuid = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 
 [[Unicode]]
 uuid = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"
 
-[[VersionParsing]]
-deps = ["Compat"]
-git-tree-sha1 = "c9d5aa108588b978bd859554660c8a5c4f2f7669"
-uuid = "81def892-9a0e-5fdd-b105-ffc91e053289"
-version = "1.1.3"
-
 [[ZipFile]]
 deps = ["BinaryProvider", "Libdl", "Printf"]
 git-tree-sha1 = "580ce62b6c14244916cc28ad54f8a2e2886f843d"
@@ -371,9 +351,9 @@ version = "0.8.3"
 
 [[Zygote]]
 deps = ["DiffRules", "FFTW", "FillArrays", "ForwardDiff", "IRTools", "InteractiveUtils", "LinearAlgebra", "MacroTools", "NNlib", "NaNMath", "Random", "Requires", "SpecialFunctions", "Statistics", "ZygoteRules"]
-git-tree-sha1 = "e4245b9c5362346e154b62842a89a18e0210b92b"
+git-tree-sha1 = "7e293d7bef87c2cf2847e99ed0da4edadb75fe90"
 uuid = "e88e6eb3-aa80-5325-afca-941959d7151f"
-version = "0.4.1"
+version = "0.4.4"
 
 [[ZygoteRules]]
 deps = ["MacroTools"]
diff --git a/src/utils.jl b/src/utils.jl
index 324d87c8..2dba21c7 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -103,6 +103,48 @@ function batchseq(xs, pad = nothing, n = maximum(length(x) for x in xs))
   [batch([xs_[j][i] for j = 1:length(xs_)]) for i = 1:n]
 end
 
+# Flattening models to weight vectors, and back
+
+function _restructure(m, xs)
+  i = 0
+  fmap(m) do x
+    x isa AbstractArray || return x
+    x = reshape(xs[i.+(1:length(x))], size(x))
+    i += length(x)
+    return x
+  end
+end
+
+"""
+    destructure(m)
+
+Flatten a model's parameters into a single weight vector.
+
+    julia> m = Chain(Dense(10, 5, σ), Dense(5, 2), softmax)
+    Chain(Dense(10, 5, σ), Dense(5, 2), softmax)
+
+    julia> θ, re = destructure(m);
+
+    julia> θ
+    67-element Array{Float32,1}:
+    -0.1407104
+    ...
+
+The second return value `re` allows you to reconstruct the original network after making
+modifications to the weight vector (for example, with a hypernetwork).
+
+    julia> re(θ .* 2)
+    Chain(Dense(10, 5, σ), Dense(5, 2), softmax)
+"""
+function destructure(m)
+  xs = Zygote.Buffer([])
+  fmap(m) do x
+    x isa AbstractArray && push!(xs, x)
+    return x
+  end
+  return vcat(vec.(copy(xs))...), p -> _restructure(m, p)
+end
+
 # Other
 
 """