ndarray: type convertion of _minus_scalar (#354)

Ref: #353
dmlc · Dec 7, 2017 · f8d4f62 · f8d4f62
1 parent ce0e237
commit f8d4f62
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/src/ndarray.jl b/src/ndarray.jl
@@ -598,13 +598,14 @@ broadcast_(::typeof(+), x::Real, y::NDArray)          = x + y
 
 Subtract a bunch of arguments from `dst`. Inplace updating.
 """
-function sub_from!(dst::NDArray{T}, arg::NDArrayOrReal) where T
+function sub_from!(dst::NDArray, arg::NDArrayOrReal)
   @assert dst.writable
   if isa(arg, Real)
-    _minus_scalar(dst, scalar = convert(T, arg), out = dst)
+    _minus_scalar(dst, scalar = arg, out = dst)
   else
     _minus!(dst, arg)
   end
+  dst
 end
 
 import Base: -

diff --git a/test/unittest/ndarray.jl b/test/unittest/ndarray.jl
@@ -281,6 +281,11 @@ function test_minus()
   @test t6 - scalar_small ≈ copy(a6 .- scalar_small)
   @test t6 - scalar_large ≈ copy(a6 .- scalar_large)
 
+  info("NDArray::minus::scalar::type convert")
+  let x = mx.NDArray([1, 2, 3])
+    @test copy(x .- π) ≈ [-2, -1, 0]
+  end
+
   info("NDArray::minus::type stablility")
   let x = mx.zeros(dims), y = mx.ones(dims)
     @inferred x - y