2 files changed, 16 insertions, 2 deletions
diff --git a/include/cru/platform/exception.hpp b/include/cru/platform/exception.hpp
index 6dae08c5..b1e505e0 100644
--- a/include/cru/platform/exception.hpp
+++ b/include/cru/platform/exception.hpp
@@ -6,6 +6,15 @@
 namespace cru::platform {
 class PlatformException : public std::runtime_error {
  public:
-  using runtime_error::runtime_error; // inherent constructors
+  using runtime_error::runtime_error;  // inherit constructors
+};
+
+// This exception is throwed when a resource has been disposed and not usable
+// again.
+// For example, calling Build twice on a GeometryBuild will lead to this
+// exception.
+class ReuseException : public std::runtime_error {
+ public:
+  using runtime_error::runtime_error;  // inherit constructors
 };
 }  // namespace cru::platform
diff --git a/include/cru/win/graph/direct/geometry.hpp b/include/cru/win/graph/direct/geometry.hpp
index f40db7af..1ee60247 100644
--- a/include/cru/win/graph/direct/geometry.hpp
+++ b/include/cru/win/graph/direct/geometry.hpp
@@ -3,6 +3,7 @@
 #include "direct_factory.hpp"
 #include "platform_id.hpp"
 
+#include "cru/platform/exception.hpp"
 #include "cru/platform/graph/geometry.hpp"
 
 namespace cru::platform::graph::win::direct {
@@ -16,7 +17,7 @@ class D2DGeometryBuilder : public GeometryBuilder {
   D2DGeometryBuilder(D2DGeometryBuilder&& other) = delete;
   D2DGeometryBuilder& operator=(D2DGeometryBuilder&& other) = delete;
 
-  ~D2DGeometryBuilder() override;
+  ~D2DGeometryBuilder() override = default;
 
   CRU_PLATFORMID_IMPLEMENT_DIRECT
 
@@ -31,6 +32,10 @@ class D2DGeometryBuilder : public GeometryBuilder {
 
  private:
   bool IsValid() { return geometry_ != nullptr; }
+  void CheckValidation() {
+    if (!IsValid())
+      throw ReuseException("The geometry builder is already disposed.");
+  }
 
  private:
   Microsoft::WRL::ComPtr<ID2D1PathGeometry> geometry_;