Fix incorrect type asssertion in real_operate (#704)

Author: odow

src/real_operate.jl

@@ -220,7 +220,7 @@ function real_operate(
     args::AllAllowedReal{T}...,
 ) where {T<:Real}
     all_args = (arg1, arg2, arg3, args...)
-    return foldl((a, b) -> real_operate(vcat, T, a, b), all_args)::SparseTape{T}
+    return foldl((a, b) -> real_operate(vcat, T, a, b), all_args)
 end
 
 function real_operate(

test/test_utilities.jl

@@ -1428,6 +1428,13 @@ function test_not_dcp_warn()
     return
 end
 
+function test_real_operate_vector()
+    x = BigFloat[0]
+    y = Convex.real_operate(vcat, BigFloat, x, x, x, x, x)
+    @test y == BigFloat[0, 0, 0, 0, 0]
+    return
+end
+
 end  # TestUtilities
 
 TestUtilities.runtests()