From fb6b521e43c018b72936af0ef190661ab2cdabd5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael-Jorge=20G=C3=B3mez=20Campos?= <michakun@gmail.com>
Date: Mon, 1 Jun 2020 15:41:58 +0200
Subject: [PATCH 1/3] Add Option.ofUnchecked function

---
 src/FSharpx.Extras/ComputationExpressions/Option.fs | 6 ++++++
 tests/FSharpx.Tests/OptionTests.fs                  | 9 +++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/FSharpx.Extras/ComputationExpressions/Option.fs b/src/FSharpx.Extras/ComputationExpressions/Option.fs
index dc4b68fe..82d14672 100644
--- a/src/FSharpx.Extras/ComputationExpressions/Option.fs
+++ b/src/FSharpx.Extras/ComputationExpressions/Option.fs
@@ -132,6 +132,12 @@ module Option =
         | Ok a -> Some a
         | _ -> None
 
+    /// Maps Unchecked object when null to None, otherwise Some value.
+    /// It's useful when getting data from external sources, pe.
+    let ofUnchecked (x: 'a) =
+        match Unchecked.defaultof<'a> = x with
+        | true -> None
+        | false -> Some x
 
     /// Gets the value associated with the option or the supplied default value.
     let inline getOrElse v =
diff --git a/tests/FSharpx.Tests/OptionTests.fs b/tests/FSharpx.Tests/OptionTests.fs
index 74ccc1d8..7c014670 100644
--- a/tests/FSharpx.Tests/OptionTests.fs
+++ b/tests/FSharpx.Tests/OptionTests.fs
@@ -94,3 +94,12 @@ let someIfBoolTestCases = [
 [<TestCaseSource(nameof someIfBoolTestCases)>]
 let ``someIf with id`` (input:bool, expectedOutput:bool option) =
     Option.someIf id input |> shouldEqual expectedOutput
+
+type UncheckedRecordTest =
+    { Dummy: int }
+
+[<Test>]
+let ``from unchecked value``() =
+    let test = { Dummy = 4 }
+    Assert.AreEqual(Some test, Option.ofUnchecked test)
+    Assert.AreEqual(None, Option.ofUnchecked (Unchecked.defaultof<UncheckedRecordTest>))
\ No newline at end of file

From 054396420ca5a801f0f51f1cb4fc2cd14e05b64b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael-Jorge=20G=C3=B3mez=20Campos?= <michakun@gmail.com>
Date: Tue, 2 Jun 2020 08:23:46 +0200
Subject: [PATCH 2/3] Ensure Option.ofUnchecked is only for non-struct values.
 Replace unchecked usage with box.

---
 src/FSharpx.Extras/ComputationExpressions/Option.fs |  4 ++--
 tests/FSharpx.Tests/OptionTests.fs                  | 12 +++++++++++-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/FSharpx.Extras/ComputationExpressions/Option.fs b/src/FSharpx.Extras/ComputationExpressions/Option.fs
index 82d14672..5ab447ee 100644
--- a/src/FSharpx.Extras/ComputationExpressions/Option.fs
+++ b/src/FSharpx.Extras/ComputationExpressions/Option.fs
@@ -134,8 +134,8 @@ module Option =
 
     /// Maps Unchecked object when null to None, otherwise Some value.
     /// It's useful when getting data from external sources, pe.
-    let ofUnchecked (x: 'a) =
-        match Unchecked.defaultof<'a> = x with
+    let inline ofUnchecked (x: 'a when 'a : not struct) =
+        match box x = null with
         | true -> None
         | false -> Some x
 
diff --git a/tests/FSharpx.Tests/OptionTests.fs b/tests/FSharpx.Tests/OptionTests.fs
index 7c014670..c6027d50 100644
--- a/tests/FSharpx.Tests/OptionTests.fs
+++ b/tests/FSharpx.Tests/OptionTests.fs
@@ -102,4 +102,14 @@ type UncheckedRecordTest =
 let ``from unchecked value``() =
     let test = { Dummy = 4 }
     Assert.AreEqual(Some test, Option.ofUnchecked test)
-    Assert.AreEqual(None, Option.ofUnchecked (Unchecked.defaultof<UncheckedRecordTest>))
\ No newline at end of file
+    Assert.AreEqual(None, Option.ofUnchecked (Unchecked.defaultof<UncheckedRecordTest>))
+
+[<NoEquality;NoComparison>] 
+type UncheckedRecordTest2 =
+    { Dummy2: int }
+
+[<Test>]
+let ``from unchecked value without equality nor comparison``() =
+    let test = { Dummy2 = 4 }
+    Assert.AreEqual(Some test, Option.ofUnchecked test)
+    Assert.AreEqual(None, Option.ofUnchecked (Unchecked.defaultof<UncheckedRecordTest2>))
\ No newline at end of file

From f53c9e156f37ccab8e9a20a25ee0013b97d9989c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michael-Jorge=20G=C3=B3mez=20Campos?= <michakun@gmail.com>
Date: Wed, 3 Jun 2020 08:49:11 +0200
Subject: [PATCH 3/3] Optimize function

---
 src/FSharpx.Extras/ComputationExpressions/Option.fs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/FSharpx.Extras/ComputationExpressions/Option.fs b/src/FSharpx.Extras/ComputationExpressions/Option.fs
index 5ab447ee..815b8eda 100644
--- a/src/FSharpx.Extras/ComputationExpressions/Option.fs
+++ b/src/FSharpx.Extras/ComputationExpressions/Option.fs
@@ -135,9 +135,9 @@ module Option =
     /// Maps Unchecked object when null to None, otherwise Some value.
     /// It's useful when getting data from external sources, pe.
     let inline ofUnchecked (x: 'a when 'a : not struct) =
-        match box x = null with
-        | true -> None
-        | false -> Some x
+        match box x with
+        | null -> None
+        | _ -> Some x
 
     /// Gets the value associated with the option or the supplied default value.
     let inline getOrElse v =