From 207cb3e9237fa6960a67aab7d05a80ffd897bb17 Mon Sep 17 00:00:00 2001
From: Niels Dekker <N.Dekker@lumc.nl>
Date: Tue, 16 Dec 2025 14:19:13 +0100
Subject: [PATCH 1/2] ENH: Add `VariableLengthVector(length, value)`
 constructor

Follow-up to pull request https://github.com/InsightSoftwareConsortium/ITK/pull/2248
commit 73ce4ca9dd73498a7f8de4d9aca3b72b1f8b59fe
"ENH: Array, OptimizerParameters constructors with size and initial value"
---
 .../Common/include/itkVariableLengthVector.h  |  3 +++
 .../include/itkVariableLengthVector.hxx       |  7 ++++++
 .../test/itkVariableLengthVectorGTest.cxx     | 22 +++++++++++++++++++
 3 files changed, 32 insertions(+)

diff --git a/Modules/Core/Common/include/itkVariableLengthVector.h b/Modules/Core/Common/include/itkVariableLengthVector.h
index 29c89953295..52cea457f7c 100644
--- a/Modules/Core/Common/include/itkVariableLengthVector.h
+++ b/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
diff --git a/Modules/Core/Common/include/itkVariableLengthVector.hxx b/Modules/Core/Common/include/itkVariableLengthVector.hxx
index 48e5b5ca41a..7ea779f5df5 100644
--- a/Modules/Core/Common/include/itkVariableLengthVector.hxx
+++ b/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)
diff --git a/Modules/Core/Common/test/itkVariableLengthVectorGTest.cxx b/Modules/Core/Common/test/itkVariableLengthVectorGTest.cxx
index 0823a4076c5..fba4b2aff2b 100644
--- a/Modules/Core/Common/test/itkVariableLengthVectorGTest.cxx
+++ b/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);
+    }
+  }
+}

From a912fac4b35281e14925510010c75bdcacb4aeff Mon Sep 17 00:00:00 2001
From: Niels Dekker <N.Dekker@lumc.nl>
Date: Tue, 16 Dec 2025 15:00:17 +0100
Subject: [PATCH 2/2] STYLE: Do return `VariableLengthVector(length, value)` in
 NumericTraits

Replaced local `b` variables and `b.Fill` calls.
---
 ...tkNumericTraitsVariableLengthVectorPixel.h | 24 ++++---------------
 1 file changed, 5 insertions(+), 19 deletions(-)

diff --git a/Modules/Core/Common/include/itkNumericTraitsVariableLengthVectorPixel.h b/Modules/Core/Common/include/itkNumericTraitsVariableLengthVectorPixel.h
index e4b09ebe453..07e2f116442 100644
--- a/Modules/Core/Common/include/itkNumericTraitsVariableLengthVectorPixel.h
+++ b/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