Update

src/Utilities/functions.jl

@@ -1541,33 +1541,110 @@ function Base.:*(f::ScalarLike, g::ScalarLike, args::ScalarLike...)
  return operate(*, T, f, g, args...)
 end
 
-function Base.:*(f::Number, g::Union{MOI.VariableIndex,MOI.VectorOfVariables})
- return operate(*, typeof(f), f, g)
-end
-
 function Base.:*(f::Union{MOI.VariableIndex,MOI.VectorOfVariables}, g::Number)
  return operate(*, typeof(g), f, g)
 end
 
-function Base.:*(f::Number, g::TypedLike)
- return operate_coefficients(Base.Fix1(*, f), g)
+function Base.:*(
+ f::Union{
+ MOI.ScalarAffineFunction{T},
+ MOI.ScalarQuadraticFunction{T},
+ MOI.VectorAffineFunction{T},
+ MOI.VectorQuadraticFunction{T},
+ },
+ g::T,
+) where {T<:Number}
+ return operate_coefficients(Base.Fix2(*, g), f)
 end
 
-function Base.:*(g::TypedLike, f::Number)
- return operate_coefficients(Base.Fix1(*, f), g)
+function Base.:*(
+ f::T,
+ g::Union{
+ MOI.VariableIndex,
+ MOI.ScalarAffineFunction{T},
+ MOI.ScalarQuadraticFunction{T},
+ MOI.VectorOfVariables,
+ MOI.VectorAffineFunction{T},
+ MOI.VectorQuadraticFunction{T},
+ },
+) where {T<:Number}
+ return g * f
 end
 
 # Used by sparse matrix multiplication after
 # https://github.com/JuliaLang/julia/pull/33205
-function Base.:*(f::TypedLike, g::Bool)
+function Base.:*(
+ f::Union{
+ MOI.ScalarAffineFunction,
+ MOI.ScalarQuadraticFunction,
+ MOI.VectorAffineFunction,
+ MOI.VectorQuadraticFunction,
+ },
+ g::Bool,
+)
  if g
  return MA.copy_if_mutable(f)
  else
  return zero(typeof(f))
  end
 end
 
-Base.:*(f::Bool, g::TypedLike) = g * f
+# These method are needed for multiplication between different number types. The
+# most common case is when the number is a `Complex{T}`.
+
+function Base.:*(
+ f::Union{
+ MOI.ScalarAffineFunction,
+ MOI.ScalarQuadraticFunction,
+ MOI.VectorAffineFunction,
+ MOI.VectorQuadraticFunction,
+ },
+ g::Number,
+)
+ return operate_coefficients(Base.Fix2(*, g), f)
+end
+
+function Base.:*(
+ f::Number,
+ g::Union{
+ MOI.VariableIndex,
+ MOI.ScalarAffineFunction,
+ MOI.ScalarQuadraticFunction,
+ MOI.VectorOfVariables,
+ MOI.VectorAffineFunction,
+ MOI.VectorQuadraticFunction,
+ },
+) where {T}
+ return g * f
+end
+
+# !!! warning
+# MathOptInterface includes these methods to support coefficient types which
+# are not subtypes of `Number`. We shoud consider removing them in MOI v2.0.
+
+function Base.:*(
+ f::Union{
+ MOI.ScalarAffineFunction{T},
+ MOI.ScalarQuadraticFunction{T},
+ MOI.VectorAffineFunction{T},
+ MOI.VectorQuadraticFunction{T},
+ },
+ g::T,
+) where {T}
+ return operate_coefficients(Base.Fix2(*, g), f)
+end
+
+function Base.:*(
+ f::T,
+ g::Union{
+ MOI.ScalarAffineFunction{T},
+ MOI.ScalarQuadraticFunction{T},
+ MOI.VectorAffineFunction{T},
+ MOI.VectorQuadraticFunction{T},
+ },
+) where {T}
+ return g * f
+end
 
 ### Base.:/