News and docs for #18965

NEWS.md

@@ -24,6 +24,9 @@ This section lists changes that do not have deprecation warnings.
   * `broadcast` now handles tuples, and treats any argument that is not a tuple
     or an array as a "scalar" ([#16986]).
 
+  * `broadcast` now treats `Ref` (except for `Ptr`) arguments as 0-dimensional
+    arrays ([#18965]).
+
 Library improvements
 --------------------
 
@@ -691,4 +694,5 @@ Language tooling improvements
 [#18442]: https://github.com/JuliaLang/julia/issues/18442
 [#18473]: https://github.com/JuliaLang/julia/issues/18473
 [#18839]: https://github.com/JuliaLang/julia/issues/18839
+[#18965]: https://github.com/JuliaLang/julia/issues/18965
 [#19018]: https://github.com/JuliaLang/julia/issues/19018

base/broadcast.jl

@@ -266,15 +266,16 @@ end
 """
     broadcast(f, As...)
 
-Broadcasts the arrays, tuples and/or scalars `As` to a container of the
+Broadcasts the arrays, tuples, `Ref` and/or scalars `As` to a container of the
 appropriate type and dimensions. In this context, anything that is not a
-subtype of `AbstractArray` or `Tuple` is considered a scalar. The resulting
-container is established by the following rules:
+subtype of `AbstractArray`, `Ref` (except for `Ptr`s) or `Tuple` is considered
+a scalar. The resulting container is established by the following rules:
 
  - If all the arguments are scalars, it returns a scalar.
  - If the arguments are tuples and zero or more scalars, it returns a tuple.
- - If there is at least an array in the arguments, it returns an array
-   (and treats tuples as 1-dimensional arrays) expanding singleton dimensions.
+ - If there is at least an array or a `Ref` in the arguments, it returns an array
+   (and treats any `Ref` as a 0-dimensional array of its contents and any tuple
+   as a 1-dimensional array) expanding singleton dimensions.
 
 A special syntax exists for broadcasting: `f.(args...)` is equivalent to
 `broadcast(f, args...)`, and nested `f.(g.(args...))` calls are fused into a
@@ -316,11 +317,16 @@ julia> abs.((1, -2))
 julia> broadcast(+, 1.0, (0, -2.0))
 (1.0,-1.0)
 
-julia> broadcast(+, 1.0, (0, -2.0), [1])
+julia> broadcast(+, 1.0, (0, -2.0), Ref(1))
 2-element Array{Float64,1}:
  2.0
  0.0
 
+julia> (+).([[0,2], [1,3]], Ref{Vector{Int}}([1,-1]))
+2-element Array{Array{Int64,1},1}:
+ [1,1]
+ [2,2]
+
 julia> string.(("one","two","three","four"), ": ", 1:4)
 4-element Array{String,1}:
  "one: 1"

doc/manual/arrays.rst

@@ -526,7 +526,7 @@ function elementwise:
 
 Elementwise operators such as ``.+`` and ``.*`` perform broadcasting if necessary. There is also a :func:`broadcast!` function to specify an explicit destination, and :func:`broadcast_getindex` and :func:`broadcast_setindex!` that broadcast the indices before indexing.   Moreover, ``f.(args...)`` is equivalent to ``broadcast(f, args...)``, providing a convenient syntax to broadcast any function (:ref:`man-dot-vectorizing`).
 
-Additionally, :func:`broadcast` is not limited to arrays (see the function documentation), it also handles tuples and treats any argument that is not an array or a tuple as a "scalar".
+Additionally, :func:`broadcast` is not limited to arrays (see the function documentation), it also handles tuples and treats any argument that is not an array, tuple or `Ref` (except for `Ptr`) as a "scalar".
 
 .. doctest::
 

doc/stdlib/arrays.rst

@@ -640,11 +640,11 @@ All mathematical operations and functions are supported for arrays
 
    .. Docstring generated from Julia source
 
-   Broadcasts the arrays, tuples and/or scalars ``As`` to a container of the appropriate type and dimensions. In this context, anything that is not a subtype of ``AbstractArray`` or ``Tuple`` is considered a scalar. The resulting container is established by the following rules:
+   Broadcasts the arrays, tuples, ``Ref`` and/or scalars ``As`` to a container of the appropriate type and dimensions. In this context, anything that is not a subtype of ``AbstractArray``\ , ``Ref`` (except for ``Ptr``\ s) or ``Tuple`` is considered a scalar. The resulting container is established by the following rules:
 
    * If all the arguments are scalars, it returns a scalar.
    * If the arguments are tuples and zero or more scalars, it returns a tuple.
-   * If there is at least an array in the arguments, it returns an array (and treats tuples as 1-dimensional arrays) expanding singleton dimensions.
+   * If there is at least an array or a ``Ref`` in the arguments, it returns an array (and treats any ``Ref`` as a 0-dimensional array of its contents and any tuple as a 1-dimensional array) expanding singleton dimensions.
 
    A special syntax exists for broadcasting: ``f.(args...)`` is equivalent to ``broadcast(f, args...)``\ , and nested ``f.(g.(args...))`` calls are fused into a single broadcast loop.
 
@@ -685,11 +685,16 @@ All mathematical operations and functions are supported for arrays
        julia> broadcast(+, 1.0, (0, -2.0))
        (1.0,-1.0)
 
-       julia> broadcast(+, 1.0, (0, -2.0), [1])
+       julia> broadcast(+, 1.0, (0, -2.0), Ref(1))
        2-element Array{Float64,1}:
         2.0
         0.0
 
+       julia> (+).([[0,2], [1,3]], Ref{Vector{Int}}([1,-1]))
+       2-element Array{Array{Int64,1},1}:
+        [1,1]
+        [2,2]
+
        julia> string.(("one","two","three","four"), ": ", 1:4)
        4-element Array{String,1}:
         "one: 1"