Fix #1556

src/layers/basic.jl

@@ -69,7 +69,7 @@ extraChain(::Tuple{}, x) = ()
 
 
 """
-    Dense(in, out, σ=identity; bias=true, init=glorot_uniform)
+    Dense(in, out, σ = identity; bias = true, init = glorot_uniform)
     Dense(W::AbstractMatrix, [bias, σ])
 
 Create a traditional `Dense` layer, whose forward pass is given by:
@@ -81,7 +81,7 @@ as an `in × N` matrix, or any array with `size(x,1) == in`.
 The out `y` will be a vector  of length `out`, or a batch with
 `size(y) == (out, size(x)[2:end]...)`
 
-Keyword `bias=false` will switch off trainable bias for the layer.
+Keyword `bias = false` will switch off trainable bias for the layer.
 The initialisation of the weight matrix is `W = init(out, in)`, calling the function
 given to keyword `init`, with default [`glorot_uniform`](@doc Flux.glorot_uniform).
 The weight matrix and/or the bias vector (of length `out`) may also be provided explicitly.
@@ -109,46 +109,42 @@ julia> Flux.params(d1)  # no trainable bias
 Params([[1.0 1.0 … 1.0 1.0; 1.0 1.0 … 1.0 1.0]])
 ```
 """
-struct Dense{F, M<:AbstractMatrix, B}
-  weight::M
-  bias::B
+struct Dense{F,S<:AbstractArray,T}
+  weight::S
+  bias::T
   σ::F
-  function Dense(W::M, bias = true, σ::F = identity) where {M<:AbstractMatrix, F}
-    b = create_bias(W, bias, size(W,1))
-    new{F,M,typeof(b)}(W, b, σ)
-  end
 end
 
-function Dense(in::Integer, out::Integer, σ = identity;
-               initW = nothing, initb = nothing,
-               init = glorot_uniform, bias=true)
+Dense(W, b) = Dense(W, b, identity)
 
-  W = if initW !== nothing
-    Base.depwarn("keyword initW is deprecated, please use init (which similarly accepts a funtion like randn)", :Dense)
-    initW(out, in)
-  else
-    init(out, in)
+Dense(W, b::Bool, σ) =
+  Dense(W, create_bias(W, b, size(W,1)), σ)
+
+function Dense(in::Integer, out::Integer, σ = identity; initW = nothing,
+               init = glorot_uniform, initb = nothing, bias::Bool = true)
+  if initW !== nothing
+    depwarn("initW is deprecated, please use the `init` keyword instead")
+    init = initW
   end
 
-  b = if bias === true && initb !== nothing
-    Base.depwarn("keyword initb is deprecated, please simply supply the bias vector, bias=initb(out)", :Dense)
-    initb(out)
+  if initb !== nothing
+    depwarn("initb is deprecated, please use the array based constructors instead")
+    initb = initb
   else
-    bias
+    initb = zeros
   end
-
-  return Dense(W, b, σ)
+  Dense(init(out, in), bias ? initb(out) : Zeros(), σ)
 end
 
 @functor Dense
 
 function (a::Dense)(x::AbstractVecOrMat)
   W, b, σ = a.weight, a.bias, a.σ
-  return σ.(W*x .+ b)
+  σ.(W * x .+ b) 
 end
 
-(a::Dense)(x::AbstractArray) = 
-  reshape(a(reshape(x, size(x,1), :)), :, size(x)[2:end]...)
+(a::Dense)(x) =
+   reshape(a(reshape(x, size(x,1), :)), :, size(x)[2:end]...)
 
 function Base.show(io::IO, l::Dense)
   print(io, "Dense(", size(l.weight, 2), ", ", size(l.weight, 1))

src/utils.jl

@@ -390,12 +390,7 @@ function create_bias(weights::AbstractArray, bias::Bool, dims::Integer...)
 end
 function create_bias(weights::AbstractArray, bias::AbstractArray, dims::Integer...)
   size(bias) == dims || throw(DimensionMismatch("expected bias of size $(dims), got size $(size(bias))"))
-  if eltype(bias) == eltype(weights)
-    return bias
-  else
-    @warn "converting bias to match element type of weights" typeof(weights) typeof(bias) maxlog=3 _id=hash(dims)
-    return broadcast(eltype(weights), bias)
-  end
+  bias
 end
 
 """