removed Flatten struct

updated documentation

docs/src/models/layers.md

@@ -20,7 +20,7 @@ GlobalMeanPool
 DepthwiseConv
 ConvTranspose
 CrossCor
-Flatten
+flatten
 ```
 
 ## Recurrent Layers

src/Flux.jl

@@ -11,7 +11,7 @@ using Zygote: Params, @adjoint, gradient, pullback, @nograd
 export gradient
 
 export Chain, Dense, Maxout, RNN, LSTM, GRU, Conv, CrossCor, ConvTranspose,
-       GlobalMaxPool, GlobalMeanPool, MaxPool, MeanPool, Flatten,
+       GlobalMaxPool, GlobalMeanPool, MaxPool, MeanPool, flatten,
        DepthwiseConv, Dropout, AlphaDropout, LayerNorm, BatchNorm, InstanceNorm, GroupNorm,
        SkipConnection, params, fmap, cpu, gpu, f32, f64, testmode!, trainmode!
 

src/layers/conv.jl

@@ -416,29 +416,3 @@ function Base.show(io::IO, m::MeanPool)
 end
 
 outdims(l::MeanPool{N}, isize) where N = output_size(PoolDims(_paddims(isize, (l.k..., 1, 1)), l.k; stride = l.stride, padding = l.pad))
-
-"""
-    Flatten()
-
-Flattening layer.
-
-Transforms (w,h,c,b)-shaped input into (w*h*c,b)-shaped output,
-by linearizing all values for each element in the batch.
-"""
-struct Flatten{F}
-  σ::F
-  function Flatten(σ::F = identity) where {F}
-    return new{F}(σ)
-  end
-end
-
-function (f::Flatten)(x::AbstractArray)
-  σ = f.σ
-  σ(flatten(x))
-end
-
-function Base.show(io::IO, f::Flatten)
-  print(io, "Flatten(")
-  f.σ == identity || print(io, f.σ)
-  print(io, ")")
-end

test/layers/conv.jl

@@ -12,8 +12,6 @@ using Flux: gradient
   @test mp(x) == maxpool(x, PoolDims(x, 2))
   mp = MeanPool((2, 2))
   @test mp(x) == meanpool(x, PoolDims(x, 2))
-  f = Flatten()
-  @test size(f(x)) == (300, 2)
 end
 
 @testset "CNN" begin