Merge pull request #513 from JuliaOpt/bl/broadcastattr

Broadcast attributes

Author: blegat

src/attributes.jl

@@ -36,6 +36,12 @@ abstract type AbstractConstraintAttribute end
 
 const AnyAttribute = Union{AbstractOptimizerAttribute, AbstractModelAttribute, AbstractVariableAttribute, AbstractConstraintAttribute}
 
+@static if VERSION >= v"0.7-"
+    # This allows to use attributes in broadcast calls without the need to
+    # embed it in a `Ref`
+    Base.broadcastable(attribute::AnyAttribute) = Ref(attribute)
+end
+
 """
     struct UnsupportedAttribute{AttrType} <: UnsupportedError
         attr::AttrType
@@ -183,7 +189,7 @@ function get end
 # We want to avoid being too specific in the type arguments to avoid method ambiguity.
 # For model, get(::ModelLike, ::AbstractVariableAttribute, ::Vector{VariableIndex}) would not allow
 # to define get(::SomeModel, ::AnyAttribute, ::Vector)
-get(model::ModelLike, attr::AnyAttribute, idxs::Vector) = get.(model, Ref(attr), idxs)
+get(model::ModelLike, attr::AnyAttribute, idxs::Vector) = get.(model, attr, idxs)
 
 function get(model::ModelLike, attr::AnyAttribute, args...)
     throw(ArgumentError("ModelLike of type $(typeof(model)) does not support accessing the attribute $attr"))
@@ -264,7 +270,12 @@ set(model, ConstraintFunction(), c, SingleVariable(v1)) # Error
 """
 function set end
 # See note with get
-set(model::ModelLike, attr::Union{AbstractVariableAttribute, AbstractConstraintAttribute}, idxs::Vector, vector_of_values::Vector) = set.(model, Ref(attr), idxs, vector_of_values)
+function set(model::ModelLike,
+             attr::Union{AbstractVariableAttribute,
+                         AbstractConstraintAttribute},
+             idxs::Vector, vector_of_values::Vector)
+    return set.(model, attr, idxs, vector_of_values)
+end
 
 function set(model::ModelLike, attr::AnyAttribute, args...)
     set_fallback_error(model, attr, args...)