Add constructor without type

Author: 1-Bart-1

NEWS.md

@@ -1,3 +1,14 @@
+## VortexStepMethod v3.3.0 2026-05-05
+
+### Added
+- `ForwardDiff` compatibility, used by default in `linearize` (#232)
+- `backend` keyword argument for `linearize`
+- example `linearize_check.jl` comparing FiniteDiff and ForwardDiff tangents
+
+### Changed
+- core structs are parameterized on the scalar type `T` so dual numbers can
+  propagate through them; public constructors are unchanged
+
 ## VortexStepMethod v3.2.0 2026-05-02
 
 ### Added

Project.toml

@@ -1,7 +1,7 @@
 name = "VortexStepMethod"
 uuid = "ed3cd733-9f0f-46a9-93e0-89b8d4998dd9"
 authors = ["1-Bart-1 <bart@vandelint.net>", "Oriol Cayon and contributors"]
-version = "3.2.0"
+version = "3.3.0"
 
 [workspace]
 projects = ["examples", "examples_cp", "docs", "test"]

src/wing_geometry.jl

@@ -30,6 +30,8 @@ and aerodynamic model.
 # Returns
 - `Section`: A new section with the specified parameters and no aerodynamic data
 """
+Section() = Section{Float64}()
+
 function Section(LE_point, TE_point, aero_model)
     return Section{Float64}(MVector{3,Float64}(LE_point), MVector{3,Float64}(TE_point), aero_model, nothing)
 end

test/wing_geometry/test_wing_geometry.jl

@@ -20,6 +20,15 @@ function ==(a::Section, b::Section)
 end
 
 @testset "Wing Geometry Tests" begin
+    @testset "Section default constructor" begin
+        s = Section()
+        @test s isa Section{Float64}
+        @test s.LE_point == zeros(3)
+        @test s.TE_point == zeros(3)
+        @test s.aero_model === INVISCID
+        @test isnothing(s.aero_data)
+    end
+
     @testset "Wing initialization" begin
         example_wing = Wing(10; spanwise_distribution=LINEAR)
         @test example_wing.n_panels == 10