From a52bf6334f6747ac1fbc60a72d49d224ca83d06c Mon Sep 17 00:00:00 2001
From: Andrei Sergeev <a.sergeev.official@gmail.com>
Date: Fri, 1 May 2026 10:29:25 +0400
Subject: [PATCH 1/3] release/v1.6.0-rc.1; minor refactor

---
 .../Factory/Factory.Constructor.Private.cs    |  2 +-
 .../Factory/Factory.Create.Internal.cs        | 20 +++++++++++++++++++
 .../FlatArray/FlatArray.csproj                |  2 +-
 .../SplitToFlatArray/SplitToFlatArray.Char.cs | 12 ++---------
 .../SplitToFlatArray.CharArray.cs             | 12 ++---------
 .../SplitToFlatArray.String.cs                | 12 ++---------
 .../SplitToFlatArray.StringArray.cs           | 12 ++---------
 .../FlatCollections/FlatCollections.csproj    |  2 +-
 8 files changed, 31 insertions(+), 43 deletions(-)
 create mode 100644 src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs

diff --git a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Constructor.Private.cs b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Constructor.Private.cs
index 2a49e93..cd27ca4 100644
--- a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Constructor.Private.cs
+++ b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Constructor.Private.cs
@@ -26,7 +26,7 @@ private FlatArray(T[] items, int _)
     // the caller MUST ensure the length is GREATER than zero
     //
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    internal FlatArray(int length, T[] items)
+    private FlatArray(int length, T[] items)
     {
         Debug.Assert(items is not null);
         Debug.Assert(length > 0 && length <= items.Length);
diff --git a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs
new file mode 100644
index 0000000..06af402
--- /dev/null
+++ b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs
@@ -0,0 +1,20 @@
+using System.Diagnostics;
+
+namespace System;
+
+partial struct FlatArray<T>
+{
+    // Initializes an instance without creation of a defensive copy
+    // When the input array is empty, the default is returned
+    internal static FlatArray<T> InternalCreate(T[] items)
+    {
+        Debug.Assert(items is not null);
+
+        if (items.Length == default)
+        {
+            return default;
+        }
+
+        return new(items, default);
+    }
+}
diff --git a/src/flatcollections-array/FlatArray/FlatArray.csproj b/src/flatcollections-array/FlatArray/FlatArray.csproj
index 4ccdb88..8c9ad15 100644
--- a/src/flatcollections-array/FlatArray/FlatArray.csproj
+++ b/src/flatcollections-array/FlatArray/FlatArray.csproj
@@ -19,7 +19,7 @@
     <Description>PrimeFuncPack Core.FlatArray is a core library for .NET consisting of immutable FlatArray targeted for use in functional programming.</Description>
     <RootNamespace>System</RootNamespace>
     <AssemblyName>PrimeFuncPack.Core.FlatArray</AssemblyName>
-    <Version>1.6.0-preview.1</Version>
+    <Version>1.6.0-rc.1</Version>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs
index 84ff0ad..328b3f5 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs
@@ -11,12 +11,8 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separator, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -28,11 +24,7 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separator, count, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs
index 9cd3a36..592f6f3 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs
@@ -11,12 +11,8 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separators, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -28,11 +24,7 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separators, count, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs
index 8898dac..bd03d16 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs
@@ -11,12 +11,8 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separator, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -28,11 +24,7 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separator, count, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs
index c633ea0..a5a2e0c 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs
@@ -11,12 +11,8 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separators, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -28,11 +24,7 @@ public static FlatArray<string> SplitToFlatArray(
         }
 
         var array = source.Split(separators, count, options);
-        if (array.Length is 0)
-        {
-            return default;
-        }
 
-        return new(array.Length, array);
+        return FlatArray<string>.InternalCreate(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections/FlatCollections/FlatCollections.csproj b/src/flatcollections/FlatCollections/FlatCollections.csproj
index 3b4cb68..235bc8e 100644
--- a/src/flatcollections/FlatCollections/FlatCollections.csproj
+++ b/src/flatcollections/FlatCollections/FlatCollections.csproj
@@ -19,7 +19,7 @@
     <Description>PrimeFuncPack Core.FlatCollections is a set of immutable Flat collections for .NET designed for developing business applications based on functional programming.</Description>
     <RootNamespace>System</RootNamespace>
     <AssemblyName>PrimeFuncPack.Core.FlatCollections</AssemblyName>
-    <Version>1.6.0-preview.1</Version>
+    <Version>1.6.0-rc.1</Version>
   </PropertyGroup>
 
   <ItemGroup>

From 3e9ff89e40370c677bc4e8434a08e3883b5bbfbb Mon Sep 17 00:00:00 2001
From: Andrei Sergeev <a.sergeev.official@gmail.com>
Date: Fri, 1 May 2026 10:36:16 +0400
Subject: [PATCH 2/3] Minor refactor (adjust InternalCreateOrDefault name)

---
 ...Create.Internal.cs => Factory.CreateOrDefault.Internal.cs} | 2 +-
 .../SplitToFlatArray/SplitToFlatArray.Char.cs                 | 4 ++--
 .../SplitToFlatArray/SplitToFlatArray.CharArray.cs            | 4 ++--
 .../SplitToFlatArray/SplitToFlatArray.String.cs               | 4 ++--
 .../SplitToFlatArray/SplitToFlatArray.StringArray.cs          | 4 ++--
 5 files changed, 9 insertions(+), 9 deletions(-)
 rename src/flatcollections-array/FlatArray/FlatArray.T/Factory/{Factory.Create.Internal.cs => Factory.CreateOrDefault.Internal.cs} (85%)

diff --git a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs
similarity index 85%
rename from src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs
rename to src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs
index 06af402..bf61535 100644
--- a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.Create.Internal.cs
+++ b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs
@@ -6,7 +6,7 @@ partial struct FlatArray<T>
 {
     // Initializes an instance without creation of a defensive copy
     // When the input array is empty, the default is returned
-    internal static FlatArray<T> InternalCreate(T[] items)
+    internal static FlatArray<T> InternalCreateOrDefault(T[] items)
     {
         Debug.Assert(items is not null);
 
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs
index 328b3f5..7b23204 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.Char.cs
@@ -12,7 +12,7 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separator, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -25,6 +25,6 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separator, count, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs
index 592f6f3..2ef488a 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.CharArray.cs
@@ -12,7 +12,7 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separators, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -25,6 +25,6 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separators, count, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs
index bd03d16..c75d21e 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.String.cs
@@ -12,7 +12,7 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separator, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -25,6 +25,6 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separator, count, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 }
\ No newline at end of file
diff --git a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs
index a5a2e0c..9e92432 100644
--- a/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs
+++ b/src/flatcollections-array/FlatArray/FlatArrayExtensions/SplitToFlatArray/SplitToFlatArray.StringArray.cs
@@ -12,7 +12,7 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separators, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 
     public static FlatArray<string> SplitToFlatArray(
@@ -25,6 +25,6 @@ public static FlatArray<string> SplitToFlatArray(
 
         var array = source.Split(separators, count, options);
 
-        return FlatArray<string>.InternalCreate(array);
+        return FlatArray<string>.InternalCreateOrDefault(array);
     }
 }
\ No newline at end of file

From d675e4978c70a2b21a557cab5bed012ff72915fb Mon Sep 17 00:00:00 2001
From: Andrei Sergeev <a.sergeev.official@gmail.com>
Date: Fri, 1 May 2026 10:39:12 +0400
Subject: [PATCH 3/3] Add AggressiveInlining to InternalCreateOrDefault

---
 .../FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs     | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs
index bf61535..0774da2 100644
--- a/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs
+++ b/src/flatcollections-array/FlatArray/FlatArray.T/Factory/Factory.CreateOrDefault.Internal.cs
@@ -1,4 +1,5 @@
 using System.Diagnostics;
+using System.Runtime.CompilerServices;
 
 namespace System;
 
@@ -6,6 +7,7 @@ partial struct FlatArray<T>
 {
     // Initializes an instance without creation of a defensive copy
     // When the input array is empty, the default is returned
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal static FlatArray<T> InternalCreateOrDefault(T[] items)
     {
         Debug.Assert(items is not null);