ENH: Add itk::MakeVectorContainer(std::vector<TElement>)

Eases making an `itk::VectorContainer` based on a specific `std::vector` instance.

Modules/Core/Common/include/itkVectorContainer.h

@@ -561,6 +561,18 @@ class ITK_TEMPLATE_EXPORT VectorContainer
  , VectorType(first, last)
  {}
 };
+
+
+/** Makes a VectorContainer that has a copy of the specified `std::vector`. */
+template <typename TElement>
+auto
+MakeVectorContainer(std::vector<TElement> stdVector)
+{
+ auto vectorContainer = VectorContainer<SizeValueType, TElement>::New();
+ vectorContainer->CastToSTLContainer() = std::move(stdVector);
+ return vectorContainer;
+}
+
 } // end namespace itk
 
 #ifndef ITK_MANUAL_INSTANTIATION

Modules/Core/Common/test/itkVectorContainerGTest.cxx

@@ -100,3 +100,38 @@ TEST(VectorContainer, HasValueOfCreatedElementAtIdentifier)
  ExpectContainerHasValueOfCreatedElementAtIdentifier(magicIdentifier, i);
  }
 }
+
+
+// Tests MakeVectorContainer.
+TEST(VectorContainer, Make)
+{
+ const auto checkCopy = [](const auto & stdVector) {
+ const auto vectorContainer = itk::MakeVectorContainer(stdVector);
+ ASSERT_NE(vectorContainer, nullptr);
+ EXPECT_EQ(vectorContainer->CastToSTLConstContainer(), stdVector);
+ };
+
+ const auto checkMove = [](auto stdVector) {
+ const auto * const originalData = stdVector.data();
+ const auto vectorContainer = itk::MakeVectorContainer(std::move(stdVector));
+
+ // After the "move", the vectorContainer should hold the original data pointer.
+ ASSERT_NE(vectorContainer, nullptr);
+ EXPECT_EQ(vectorContainer->CastToSTLConstContainer().data(), originalData);
+ };
+
+ checkCopy(std::vector<int>());
+ checkCopy(std::vector<int>{ 0, 1 });
+ checkCopy(std::vector<double>());
+ checkCopy(std::vector<double>{ std::numeric_limits<double>::lowest(),
+ std::numeric_limits<double>::denorm_min(),
+ std::numeric_limits<double>::min(),
+ std::numeric_limits<double>::epsilon(),
+ std::numeric_limits<double>::max() });
+
+ for (const unsigned int numberOfElements : { 1, 2 })
+ {
+ checkMove(std::vector<int>(numberOfElements));
+ checkMove(std::vector<double>(numberOfElements));
+ }
+}