Add VariableLengthVector(length, value) constructor

Modules/Core/Common/include/itkNumericTraitsVariableLengthVectorPixel.h

@@ -95,45 +95,31 @@ class NumericTraits<VariableLengthVector<T>>
   static const Self
   max(const Self & a)
   {
-    Self b(a.Size());
-
-    b.Fill(NumericTraits<T>::max());
-    return b;
+    return Self(a.Size(), NumericTraits<T>::max());
   }
 
   static const Self
   min(const Self & a)
   {
-    Self b(a.Size());
-
-    b.Fill(NumericTraits<T>::min());
-    return b;
+    return Self(a.Size(), NumericTraits<T>::min());
   }
 
   static const Self
   ZeroValue(const Self & a)
   {
-    Self b(a.Size());
-
-    b.Fill(T{});
-    return b;
+    return Self(a.Size(), T{});
   }
 
   static const Self
   OneValue(const Self & a)
   {
-    Self b(a.Size());
-
-    b.Fill(NumericTraits<T>::OneValue());
-    return b;
+    return Self(a.Size(), NumericTraits<T>::OneValue());
   }
 
   static const Self
   NonpositiveMin(const Self & a)
   {
-    Self b(a.Size());
-    b.Fill(NumericTraits<T>::NonpositiveMin());
-    return b;
+    return Self(a.Size(), NumericTraits<T>::NonpositiveMin());
   }
 
   static bool

Modules/Core/Common/include/itkVariableLengthVector.h

@@ -344,6 +344,9 @@ class ITK_TEMPLATE_EXPORT VariableLengthVector
    */
   explicit VariableLengthVector(unsigned int length);
 
+  /** Constructor with size and initial value for each element. */
+  explicit VariableLengthVector(unsigned int length, const TValue & value);
+
   /** Constructor that initializes array with contents from a user supplied
    * buffer.
    * The pointer to the buffer and the length is specified. By default, the

Modules/Core/Common/include/itkVariableLengthVector.hxx

@@ -35,6 +35,13 @@ VariableLengthVector<TValue>::VariableLengthVector(unsigned int length)
   itkAssertInDebugAndIgnoreInReleaseMacro(m_Data != nullptr);
 }
 
+template <typename TValue>
+VariableLengthVector<TValue>::VariableLengthVector(unsigned int length, const TValue & value)
+  : VariableLengthVector(length)
+{
+  std::fill_n(m_Data, length, value);
+}
+
 template <typename TValue>
 VariableLengthVector<TValue>::VariableLengthVector(ValueType * datain, unsigned int sz, bool LetArrayManageMemory)
   : m_LetArrayManageMemory(LetArrayManageMemory)

Modules/Core/Common/test/itkVariableLengthVectorGTest.cxx

@@ -140,3 +140,25 @@ TEST(VariableLengthVector, ReverseIteration)
     }
   }
 }
+
+
+// Tests constructing with the specified length and value.
+TEST(VariableLengthVector, ConstructWithSpecifiedLengthAndValue)
+{
+  using ValueType = int;
+  using VariableLengthVectorType = itk::VariableLengthVector<ValueType>;
+  using ValueLimits = std::numeric_limits<ValueType>;
+
+  for (const auto value : { ValueLimits::min(), ValueType{}, ValueType{ 1 }, ValueLimits::max() })
+  {
+    EXPECT_TRUE(VariableLengthVectorType(0, value).empty());
+
+    for (unsigned int length{ 1 }; length < 4; ++length)
+    {
+      const VariableLengthVectorType variableLengthVector(length, value);
+
+      EXPECT_EQ(variableLengthVector.size(), length);
+      EXPECT_EQ(std::count(variableLengthVector.cbegin(), variableLengthVector.cend(), value), length);
+    }
+  }
+}