From 3cc82a51d8bc8ab72a55e0ec18e26e02f20a8fef Mon Sep 17 00:00:00 2001
From: Leonard Hecker <lhecker@microsoft.com>
Date: Sat, 30 Mar 2024 00:15:46 +0100
Subject: [PATCH] Replace til::some with til::small_vector (#16952)

`til::small_vector` had a bug: Its internal backing buffer didn't
prevent default initialization! Wrapping it in an `union` fixed that.

`til::some` had the same issue, but thinking about it I realized we
don't need both classes to exist, so I removed `til::some` since
`til::small_vector` is more flexible.

Checking the assembly, I noticed that `til::small_vector` with the
`union` fix produced a more compact result. I also noticed that in
combination with function calls and inlining the bit-wise ANDs in
the point/size/rect boolean operators produced poor-ish results.
Since their impact on performance is negligible to begin with I
simplified that code slightly.

Finally, I noticed that the boolean operator for `til::point`
was incorrect since it checked for `>0` instead of `>=0`.
Luckily nothing seemed to have used that operator yet.
(= No inbox regression.)
---
 src/inc/til/point.h                           |   2 +-
 src/inc/til/rect.h                            |  18 +-
 src/inc/til/rle.h                             |   2 -
 src/inc/til/size.h                            |   2 +-
 src/inc/til/small_vector.h                    |   7 +-
 src/inc/til/some.h                            | 267 --------------
 src/renderer/atlas/BackendD3D.h               |   1 -
 src/renderer/gdi/paint.cpp                    |   2 -
 src/server/ApiMessage.h                       |   2 -
 src/til/ut_til/BitmapTests.cpp                |   8 +-
 src/til/ut_til/PointTests.cpp                 |  18 +
 src/til/ut_til/RectangleTests.cpp             |  64 ++--
 src/til/ut_til/SizeTests.cpp                  |  30 +-
 src/til/ut_til/SmallVectorTests.cpp           |   2 -
 src/til/ut_til/SomeTests.cpp                  | 340 ------------------
 src/til/ut_til/UnicodeTests.cpp               |   4 +-
 src/til/ut_til/sources                        |   1 -
 src/til/ut_til/til.unit.tests.vcxproj         |   4 +-
 src/til/ut_til/til.unit.tests.vcxproj.filters |   6 +-
 src/types/inc/IInputEvent.hpp                 |   2 -
 src/types/inc/viewport.hpp                    |   2 +-
 21 files changed, 77 insertions(+), 707 deletions(-)
 delete mode 100644 src/inc/til/some.h
 delete mode 100644 src/til/ut_til/SomeTests.cpp

diff --git a/src/inc/til/point.h b/src/inc/til/point.h
index 4da8d5c6ddb..678afe706f6 100644
--- a/src/inc/til/point.h
+++ b/src/inc/til/point.h
@@ -58,7 +58,7 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
 
         constexpr explicit operator bool() const noexcept
         {
-            return (x > 0) & (y > 0);
+            return x >= 0 && y >= 0;
         }
 
         constexpr bool operator<(const point other) const noexcept
diff --git a/src/inc/til/rect.h b/src/inc/til/rect.h
index 7ad7fe7ab7d..bc7b07b6c83 100644
--- a/src/inc/til/rect.h
+++ b/src/inc/til/rect.h
@@ -4,11 +4,11 @@
 #pragma once
 
 #include "bit.h"
-#include "some.h"
 #include "math.h"
 #include "size.h"
 #include "point.h"
 #include "operators.h"
+#include "small_vector.h"
 
 namespace til // Terminal Implementation Library. Also: "Today I Learned"
 {
@@ -31,8 +31,7 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
 
         explicit constexpr operator bool() const noexcept
         {
-            return (left >= 0) & (top >= 0) &
-                   (right >= left) & (bottom >= top);
+            return left >= 0 && top >= 0 && right >= left && bottom >= top;
         }
     };
 
@@ -204,8 +203,7 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
 
         explicit constexpr operator bool() const noexcept
         {
-            return (left >= 0) & (top >= 0) &
-                   (right > left) & (bottom > top);
+            return left >= 0 && top >= 0 && right > left && bottom > top;
         }
 
         constexpr const_iterator begin() const
@@ -294,9 +292,9 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
         }
 
         // - = subtract
-        constexpr some<rect, 4> operator-(const rect& other) const
+        small_vector<rect, 4> operator-(const rect& other) const
         {
-            some<rect, 4> result;
+            small_vector<rect, 4> result;
 
             // We could have up to four rectangles describing the area resulting when you take removeMe out of main.
             // Find the intersection of the two so we know which bits of removeMe are actually applicable
@@ -566,14 +564,12 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
 
         constexpr bool contains(point pt) const noexcept
         {
-            return (pt.x >= left) & (pt.x < right) &
-                   (pt.y >= top) & (pt.y < bottom);
+            return pt.x >= left && pt.x < right && pt.y >= top && pt.y < bottom;
         }
 
         constexpr bool contains(const rect& rc) const noexcept
         {
-            return (rc.left >= left) & (rc.top >= top) &
-                   (rc.right <= right) & (rc.bottom <= bottom);
+            return rc.left >= left && rc.top >= top && rc.right <= right && rc.bottom <= bottom;
         }
 
         template<typename T = CoordType>
diff --git a/src/inc/til/rle.h b/src/inc/til/rle.h
index 34b6c929a0b..99bdf734c45 100644
--- a/src/inc/til/rle.h
+++ b/src/inc/til/rle.h
@@ -3,8 +3,6 @@
 
 #pragma once
 
-#include "small_vector.h"
-
 #ifdef UNIT_TESTING
 class RunLengthEncodingTests;
 #endif
diff --git a/src/inc/til/size.h b/src/inc/til/size.h
index 72dbb602852..98800ad7539 100644
--- a/src/inc/til/size.h
+++ b/src/inc/til/size.h
@@ -39,7 +39,7 @@ namespace til // Terminal Implementation Library. Also: "Today I Learned"
 
         constexpr explicit operator bool() const noexcept
         {
-            return (width > 0) & (height > 0);
+            return width > 0 && height > 0;
         }
 
         constexpr size operator+(const size other) const
diff --git a/src/inc/til/small_vector.h b/src/inc/til/small_vector.h
index f078d37fbe4..b47cd1ead14 100644
--- a/src/inc/til/small_vector.h
+++ b/src/inc/til/small_vector.h
@@ -652,7 +652,7 @@ namespace til
         reference emplace_back(Args&&... args)
         {
             const auto new_size = _ensure_fits(1);
-            const auto it = new (_data + _size) T(std::forward<Args>(args)...);
+            const auto it = std::construct_at(_data + _size, std::forward<Args>(args)...);
             _size = new_size;
             return *it;
         }
@@ -930,7 +930,10 @@ namespace til
         T* _data;
         size_t _capacity;
         size_t _size;
-        T _buffer[N];
+        union
+        {
+            T _buffer[N];
+        };
     };
 }
 
diff --git a/src/inc/til/some.h b/src/inc/til/some.h
deleted file mode 100644
index ec34a470ca4..00000000000
--- a/src/inc/til/some.h
+++ /dev/null
@@ -1,267 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-
-#pragma once
-
-#include <array>
-
-namespace til // Terminal Implementation Library. Also: "Today I Learned"
-{
-    template<class T, size_t N>
-    class some
-    {
-    private:
-        std::array<T, N> _array;
-        size_t _used;
-
-#ifdef UNIT_TESTING
-        friend class SomeTests;
-#endif
-
-    public:
-        using value_type = T;
-        using size_type = size_t;
-        using difference_type = ptrdiff_t;
-        using pointer = T*;
-        using const_pointer = const T*;
-        using reference = T&;
-        using const_reference = const T&;
-
-        using iterator = typename decltype(_array)::iterator;
-        using const_iterator = typename decltype(_array)::const_iterator;
-
-        using reverse_iterator = typename decltype(_array)::reverse_iterator;
-        using const_reverse_iterator = typename decltype(_array)::const_reverse_iterator;
-
-        constexpr some() noexcept :
-            _array{},
-            _used{ 0 }
-        {
-        }
-
-        constexpr some(std::initializer_list<T> init)
-        {
-            if (init.size() > N)
-            {
-                _invalidArg();
-            }
-
-            std::copy(init.begin(), init.end(), _array.begin());
-            _used = init.size();
-        }
-
-        constexpr bool operator==(const til::some<T, N>& other) const noexcept
-        {
-            return std::equal(cbegin(), cend(), other.cbegin(), other.cend());
-        }
-
-        constexpr bool operator!=(const til::some<T, N>& other) const noexcept
-        {
-            return !(*this == other);
-        }
-
-        constexpr void fill(const T& _Value)
-        {
-            _array.fill(_Value);
-            _used = N;
-        }
-
-        constexpr void swap(some& _Other) noexcept(std::is_nothrow_swappable_v<T>)
-        {
-            _array.swap(_Other._array);
-            std::swap(_used, _Other._used);
-        }
-
-        constexpr const_iterator begin() const noexcept
-        {
-            return _array.begin();
-        }
-
-        constexpr const_iterator end() const noexcept
-        {
-            return _array.begin() + _used;
-        }
-
-        constexpr const_reverse_iterator rbegin() const noexcept
-        {
-            return const_reverse_iterator(end());
-        }
-
-        constexpr const_reverse_iterator rend() const noexcept
-        {
-            return const_reverse_iterator(begin());
-        }
-
-        constexpr const_iterator cbegin() const noexcept
-        {
-            return begin();
-        }
-
-        constexpr const_iterator cend() const noexcept
-        {
-            return end();
-        }
-
-        constexpr const_reverse_iterator crbegin() const noexcept
-        {
-            return rbegin();
-        }
-
-        constexpr const_reverse_iterator crend() const noexcept
-        {
-            return rend();
-        }
-
-        constexpr size_type size() const noexcept
-        {
-            return _used;
-        }
-
-        constexpr size_type max_size() const noexcept
-        {
-            return N;
-        }
-
-        constexpr bool empty() const noexcept
-        {
-            return !_used;
-        }
-
-        constexpr void clear() noexcept
-        {
-            _used = 0;
-            _array = {}; // should free members, if necessary.
-        }
-
-        constexpr const_reference at(size_type pos) const
-        {
-            if (_used <= pos)
-            {
-                _outOfRange();
-            }
-
-            return _array[pos];
-        }
-
-        constexpr const_reference operator[](size_type pos) const noexcept
-        {
-            return _array[pos];
-        }
-
-        constexpr const_reference front() const noexcept
-        {
-            return _array[0];
-        }
-
-        constexpr const_reference back() const noexcept
-        {
-            return _array[_used - 1];
-        }
-
-        constexpr const T* data() const noexcept
-        {
-            return _array.data();
-        }
-
-        constexpr void push_back(const T& val)
-        {
-            if (_used >= N)
-            {
-                _outOfRange();
-            }
-
-            til::at(_array, _used) = val;
-
-            ++_used;
-        }
-
-        constexpr void push_back(T&& val)
-        {
-            if (_used >= N)
-            {
-                _outOfRange();
-            }
-
-            til::at(_array, _used) = std::move(val);
-
-            ++_used;
-        }
-
-        constexpr void pop_back()
-        {
-            if (_used <= 0)
-            {
-                _outOfRange();
-            }
-
-            --_used;
-
-            til::at(_array, _used) = 0;
-        }
-
-        [[noreturn]] constexpr void _invalidArg() const
-        {
-            throw std::invalid_argument("invalid argument");
-        }
-
-        [[noreturn]] constexpr void _outOfRange() const
-        {
-            throw std::out_of_range("invalid some<T, N> subscript");
-        }
-
-        std::wstring to_string() const
-        {
-            std::wstringstream wss;
-            wss << std::endl
-                << L"Some contains " << size() << " of max size " << max_size() << ":" << std::endl;
-            wss << L"Elements:" << std::endl;
-
-            for (auto& item : *this)
-            {
-                wss << L"\t- " << item.to_string() << std::endl;
-            }
-
-            return wss.str();
-        }
-    };
-}
-
-#ifdef __WEX_COMMON_H__
-namespace WEX::TestExecution
-{
-    template<class T, size_t N>
-    class VerifyOutputTraits<::til::some<T, N>>
-    {
-    public:
-        static WEX::Common::NoThrowString ToString(const ::til::some<T, N>& some)
-        {
-            return WEX::Common::NoThrowString(some.to_string().c_str());
-        }
-    };
-
-    template<class T, size_t N>
-    class VerifyCompareTraits<::til::some<T, N>, ::til::some<T, N>>
-    {
-    public:
-        static bool AreEqual(const ::til::some<T, N>& expected, const ::til::some<T, N>& actual) noexcept
-        {
-            return expected == actual;
-        }
-
-        static bool AreSame(const ::til::some<T, N>& expected, const ::til::some<T, N>& actual) noexcept
-        {
-            return &expected == &actual;
-        }
-
-        static bool IsLessThan(const ::til::some<T, N>& expectedLess, const ::til::some<T, N>& expectedGreater) = delete;
-
-        static bool IsGreaterThan(const ::til::some<T, N>& expectedGreater, const ::til::some<T, N>& expectedLess) = delete;
-
-        static bool IsNull(const ::til::some<T, N>& object) noexcept
-        {
-            return object == til::some<T, N>{};
-        }
-    };
-
-};
-#endif
diff --git a/src/renderer/atlas/BackendD3D.h b/src/renderer/atlas/BackendD3D.h
index 25833b831dc..6a12e704a4d 100644
--- a/src/renderer/atlas/BackendD3D.h
+++ b/src/renderer/atlas/BackendD3D.h
@@ -5,7 +5,6 @@
 
 #include <stb_rect_pack.h>
 #include <til/flat_set.h>
-#include <til/small_vector.h>
 
 #include "Backend.h"
 
diff --git a/src/renderer/gdi/paint.cpp b/src/renderer/gdi/paint.cpp
index 29f8dfc43ad..c449b4d0835 100644
--- a/src/renderer/gdi/paint.cpp
+++ b/src/renderer/gdi/paint.cpp
@@ -4,8 +4,6 @@
 #include "precomp.h"
 #include "gdirenderer.hpp"
 
-#include <til/small_vector.h>
-
 #include "../inc/unicode.hpp"
 
 #pragma hdrstop
diff --git a/src/server/ApiMessage.h b/src/server/ApiMessage.h
index d730cff9e00..6c1809aa9d7 100644
--- a/src/server/ApiMessage.h
+++ b/src/server/ApiMessage.h
@@ -20,8 +20,6 @@ Revision History:
 #include "ApiMessageState.h"
 #include "IApiRoutines.h"
 
-#include <til/small_vector.h>
-
 class ConsoleProcessHandle;
 class ConsoleHandleData;
 
diff --git a/src/til/ut_til/BitmapTests.cpp b/src/til/ut_til/BitmapTests.cpp
index ee093f52a79..b17bf0fff4e 100644
--- a/src/til/ut_til/BitmapTests.cpp
+++ b/src/til/ut_til/BitmapTests.cpp
@@ -868,7 +868,7 @@ class BitmapTests
         // C _ D D
         // _ _ E _
         // _ F F _
-        til::some<til::rect, 6> expected;
+        std::vector<til::rect> expected;
         expected.push_back(til::rect{ til::point{ 0, 0 }, til::size{ 2, 1 } });
         expected.push_back(til::rect{ til::point{ 3, 0 }, til::size{ 1, 1 } });
         expected.push_back(til::rect{ til::point{ 0, 1 }, til::size{ 1, 1 } });
@@ -877,7 +877,7 @@ class BitmapTests
         expected.push_back(til::rect{ til::point{ 1, 3 }, til::size{ 2, 1 } });
 
         Log::Comment(L"Run the iterator and collect the runs.");
-        til::some<til::rect, 6> actual;
+        std::vector<til::rect> actual;
         for (auto run : map.runs())
         {
             actual.push_back(run);
@@ -1006,7 +1006,7 @@ class BitmapTests
         // C _ D D
         // _ _ E _
         // _ F F _
-        til::some<til::rect, 6> expected;
+        std::vector<til::rect> expected;
         expected.push_back(til::rect{ til::point{ 0, 0 }, til::size{ 2, 1 } });
         expected.push_back(til::rect{ til::point{ 3, 0 }, til::size{ 1, 1 } });
         expected.push_back(til::rect{ til::point{ 0, 1 }, til::size{ 1, 1 } });
@@ -1015,7 +1015,7 @@ class BitmapTests
         expected.push_back(til::rect{ til::point{ 1, 3 }, til::size{ 2, 1 } });
 
         Log::Comment(L"Run the iterator and collect the runs.");
-        til::some<til::rect, 6> actual;
+        std::vector<til::rect> actual;
         for (auto run : map.runs())
         {
             actual.push_back(run);
diff --git a/src/til/ut_til/PointTests.cpp b/src/til/ut_til/PointTests.cpp
index cd069153c77..738847cee75 100644
--- a/src/til/ut_til/PointTests.cpp
+++ b/src/til/ut_til/PointTests.cpp
@@ -221,6 +221,24 @@ class PointTests
         }
     }
 
+    TEST_METHOD(Boolean)
+    {
+        SetVerifyOutput verifyOutputScope{ VerifyOutputSettings::LogOnlyFailures };
+
+        static constexpr til::CoordType values[] = { til::CoordTypeMin, -1, 0, 1, til::CoordTypeMax };
+
+        for (const auto x : values)
+        {
+            for (const auto y : values)
+            {
+                const til::point p{ x, y };
+                const auto expected = x >= 0 && y >= 0;
+                const auto actual = static_cast<bool>(p);
+                VERIFY_ARE_EQUAL(expected, actual);
+            }
+        }
+    }
+
     TEST_METHOD(Addition)
     {
         Log::Comment(L"Addition of two things that should be in bounds.");
diff --git a/src/til/ut_til/RectangleTests.cpp b/src/til/ut_til/RectangleTests.cpp
index 8709d1f8d66..f7a882fb987 100644
--- a/src/til/ut_til/RectangleTests.cpp
+++ b/src/til/ut_til/RectangleTests.cpp
@@ -300,22 +300,26 @@ class RectangleTests
 
     TEST_METHOD(Boolean)
     {
-        BEGIN_TEST_METHOD_PROPERTIES()
-            TEST_METHOD_PROPERTY(L"Data:left", L"{0,10}")
-            TEST_METHOD_PROPERTY(L"Data:top", L"{0,10}")
-            TEST_METHOD_PROPERTY(L"Data:right", L"{0,10}")
-            TEST_METHOD_PROPERTY(L"Data:bottom", L"{0,10}")
-        END_TEST_METHOD_PROPERTIES()
+        SetVerifyOutput verifyOutputScope{ VerifyOutputSettings::LogOnlyFailures };
 
-        til::CoordType left, top, right, bottom;
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"left", left));
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"top", top));
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"right", right));
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"bottom", bottom));
+        static constexpr til::CoordType values[] = { til::CoordTypeMin, -1, 0, 1, til::CoordTypeMax };
 
-        const auto expected = left < right && top < bottom;
-        const til::rect actual{ left, top, right, bottom };
-        VERIFY_ARE_EQUAL(expected, (bool)actual);
+        for (const auto left : values)
+        {
+            for (const auto top : values)
+            {
+                for (const auto right : values)
+                {
+                    for (const auto bottom : values)
+                    {
+                        const til::rect r{ left, top, right, bottom };
+                        const auto expected = left >= 0 && top >= 0 && right > left && bottom > top;
+                        const auto actual = static_cast<bool>(r);
+                        VERIFY_ARE_EQUAL(expected, actual);
+                    }
+                }
+            }
+        }
     }
 
     TEST_METHOD(OrUnion)
@@ -364,7 +368,7 @@ class RectangleTests
         const auto removal = original;
 
         // Since it's the same rectangle, nothing's left. We should get no results.
-        const til::some<til::rect, 4> expected;
+        const til::small_vector<til::rect, 4> expected;
         const auto actual = original - removal;
         VERIFY_ARE_EQUAL(expected, actual);
     }
@@ -375,7 +379,7 @@ class RectangleTests
         const til::rect removal{ 12, 12, 15, 15 };
 
         // Since they don't overlap, we expect the original to be given back.
-        const til::some<til::rect, 4> expected{ original };
+        const til::small_vector<til::rect, 4> expected{ original };
         const auto actual = original - removal;
         VERIFY_ARE_EQUAL(expected, actual);
     }
@@ -401,7 +405,7 @@ class RectangleTests
         const til::rect original{ 0, 0, 10, 10 };
         const til::rect removal{ -12, 3, 15, 15 };
 
-        const til::some<til::rect, 4> expected{
+        const til::small_vector<til::rect, 4> expected{
             til::rect{ original.left, original.top, original.right, removal.top }
         };
         const auto actual = original - removal;
@@ -428,7 +432,7 @@ class RectangleTests
         const til::rect original{ 0, 0, 10, 10 };
         const til::rect removal{ 3, 3, 15, 15 };
 
-        const til::some<til::rect, 4> expected{
+        const til::small_vector<til::rect, 4> expected{
             til::rect{ original.left, original.top, original.right, removal.top },
             til::rect{ original.left, removal.top, removal.left, original.bottom }
         };
@@ -452,7 +456,7 @@ class RectangleTests
         const til::rect original{ 0, 0, 10, 10 };
         const til::rect removal{ 3, 3, 15, 6 };
 
-        const til::some<til::rect, 4> expected{
+        const til::small_vector<til::rect, 4> expected{
             til::rect{ original.left, original.top, original.right, removal.top },
             til::rect{ original.left, removal.bottom, original.right, original.bottom },
             til::rect{ original.left, removal.top, removal.left, removal.bottom }
@@ -483,7 +487,7 @@ class RectangleTests
         const til::rect original{ 0, 0, 10, 10 };
         const til::rect removal{ 3, 3, 6, 6 };
 
-        const til::some<til::rect, 4> expected{
+        const til::small_vector<til::rect, 4> expected{
             til::rect{ original.left, original.top, original.right, removal.top },
             til::rect{ original.left, removal.bottom, original.right, original.bottom },
             til::rect{ original.left, removal.top, removal.left, removal.bottom },
@@ -706,26 +710,6 @@ class RectangleTests
         VERIFY_ARE_EQUAL(expected, rc.size());
     }
 
-    TEST_METHOD(Empty)
-    {
-        BEGIN_TEST_METHOD_PROPERTIES()
-            TEST_METHOD_PROPERTY(L"Data:left", L"{0,10}")
-            TEST_METHOD_PROPERTY(L"Data:top", L"{0,10}")
-            TEST_METHOD_PROPERTY(L"Data:right", L"{0,10}")
-            TEST_METHOD_PROPERTY(L"Data:bottom", L"{0,10}")
-        END_TEST_METHOD_PROPERTIES()
-
-        til::CoordType left, top, right, bottom;
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"left", left));
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"top", top));
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"right", right));
-        VERIFY_SUCCEEDED_RETURN(TestData::TryGetValue(L"bottom", bottom));
-
-        const auto expected = !(left < right && top < bottom);
-        const til::rect actual{ left, top, right, bottom };
-        VERIFY_ARE_EQUAL(expected, actual.empty());
-    }
-
     TEST_METHOD(ContainsPoint)
     {
         BEGIN_TEST_METHOD_PROPERTIES()
diff --git a/src/til/ut_til/SizeTests.cpp b/src/til/ut_til/SizeTests.cpp
index a75b48922a2..dce512aa1a7 100644
--- a/src/til/ut_til/SizeTests.cpp
+++ b/src/til/ut_til/SizeTests.cpp
@@ -147,26 +147,20 @@ class SizeTests
 
     TEST_METHOD(Boolean)
     {
-        const til::size empty;
-        VERIFY_IS_FALSE(!!empty);
+        SetVerifyOutput verifyOutputScope{ VerifyOutputSettings::LogOnlyFailures };
 
-        const til::size yOnly{ 0, 10 };
-        VERIFY_IS_FALSE(!!yOnly);
+        static constexpr til::CoordType values[] = { til::CoordTypeMin, -1, 0, 1, til::CoordTypeMax };
 
-        const til::size xOnly{ 10, 0 };
-        VERIFY_IS_FALSE(!!xOnly);
-
-        const til::size both{ 10, 10 };
-        VERIFY_IS_TRUE(!!both);
-
-        const til::size yNegative{ 10, -10 };
-        VERIFY_IS_FALSE(!!yNegative);
-
-        const til::size xNegative{ -10, 10 };
-        VERIFY_IS_FALSE(!!xNegative);
-
-        const til::size bothNegative{ -10, -10 };
-        VERIFY_IS_FALSE(!!bothNegative);
+        for (const auto width : values)
+        {
+            for (const auto height : values)
+            {
+                const til::size s{ width, height };
+                const auto expected = width > 0 && height > 0;
+                const auto actual = static_cast<bool>(s);
+                VERIFY_ARE_EQUAL(expected, actual);
+            }
+        }
     }
 
     TEST_METHOD(Addition)
diff --git a/src/til/ut_til/SmallVectorTests.cpp b/src/til/ut_til/SmallVectorTests.cpp
index f1a2ed88e54..55a338ae86d 100644
--- a/src/til/ut_til/SmallVectorTests.cpp
+++ b/src/til/ut_til/SmallVectorTests.cpp
@@ -3,8 +3,6 @@
 
 #include "precomp.h"
 
-#include <til/small_vector.h>
-
 using namespace std::literals;
 using namespace WEX::Common;
 using namespace WEX::Logging;
diff --git a/src/til/ut_til/SomeTests.cpp b/src/til/ut_til/SomeTests.cpp
deleted file mode 100644
index 98ea25fd64d..00000000000
--- a/src/til/ut_til/SomeTests.cpp
+++ /dev/null
@@ -1,340 +0,0 @@
-// Copyright (c) Microsoft Corporation.
-// Licensed under the MIT license.
-
-#include "precomp.h"
-
-using namespace WEX::Common;
-using namespace WEX::Logging;
-using namespace WEX::TestExecution;
-
-class SomeTests
-{
-    TEST_CLASS(SomeTests);
-
-    TEST_METHOD(Construct)
-    {
-        Log::Comment(L"Default Constructor");
-        til::some<int, 2> s;
-
-        Log::Comment(L"Valid Initializer List Constructor");
-        til::some<int, 2> t{ 1 };
-        til::some<int, 2> u{ 1, 2 };
-
-        Log::Comment(L"Invalid Initializer List Constructor");
-        auto f = []() {
-            til::some<int, 2> v{ 1, 2, 3 };
-        };
-
-        VERIFY_THROWS(f(), std::invalid_argument);
-    }
-
-    TEST_METHOD(Equality)
-    {
-        til::some<int, 2> a{ 1, 2 };
-        til::some<int, 2> b{ 1, 2 };
-        VERIFY_IS_TRUE(a == b);
-
-        til::some<int, 2> c{ 3, 2 };
-        VERIFY_IS_FALSE(a == c);
-
-        til::some<int, 2> d{ 2, 3 };
-        VERIFY_IS_FALSE(a == d);
-
-        til::some<int, 2> e{ 1 };
-        VERIFY_IS_FALSE(a == e);
-    }
-
-    TEST_METHOD(Inequality)
-    {
-        til::some<int, 2> a{ 1, 2 };
-        til::some<int, 2> b{ 1, 2 };
-        VERIFY_IS_FALSE(a != b);
-
-        til::some<int, 2> c{ 3, 2 };
-        VERIFY_IS_TRUE(a != c);
-
-        til::some<int, 2> d{ 2, 3 };
-        VERIFY_IS_TRUE(a != d);
-
-        til::some<int, 2> e{ 1 };
-        VERIFY_IS_TRUE(a != e);
-    }
-
-    TEST_METHOD(Fill)
-    {
-        til::some<int, 4> s;
-
-        const auto val = 12;
-        s.fill(val);
-
-        VERIFY_ARE_EQUAL(s.max_size(), s.size());
-
-        for (const auto& i : s)
-        {
-            VERIFY_ARE_EQUAL(val, i);
-        }
-    }
-
-    TEST_METHOD(Swap)
-    {
-        til::some<int, 4> a;
-        til::some<int, 4> b;
-
-        const auto aVal = 900;
-        a.fill(900);
-
-        const auto bVal = 45;
-        b.push_back(45);
-
-        const auto aSize = a.size();
-        const auto bSize = b.size();
-
-        a.swap(b);
-
-        VERIFY_ARE_EQUAL(aSize, b.size());
-        VERIFY_ARE_EQUAL(bSize, a.size());
-
-        VERIFY_ARE_EQUAL(bVal, a[0]);
-
-        for (const auto& i : b)
-        {
-            VERIFY_ARE_EQUAL(aVal, i);
-        }
-    }
-
-    TEST_METHOD(Size)
-    {
-        til::some<int, 2> c;
-
-        VERIFY_ARE_EQUAL(0u, c.size());
-
-        c.push_back(3);
-        VERIFY_ARE_EQUAL(1u, c.size());
-
-        c.push_back(12);
-        VERIFY_ARE_EQUAL(2u, c.size());
-
-        c.pop_back();
-        VERIFY_ARE_EQUAL(1u, c.size());
-
-        c.pop_back();
-        VERIFY_ARE_EQUAL(0u, c.size());
-    }
-
-    TEST_METHOD(MaxSize)
-    {
-        til::some<int, 2> c;
-
-        VERIFY_ARE_EQUAL(2u, c.max_size());
-
-        c.push_back(3);
-        VERIFY_ARE_EQUAL(2u, c.max_size());
-
-        c.push_back(12);
-        VERIFY_ARE_EQUAL(2u, c.size());
-
-        c.pop_back();
-        VERIFY_ARE_EQUAL(2u, c.max_size());
-
-        c.pop_back();
-        VERIFY_ARE_EQUAL(2u, c.max_size());
-    }
-
-    TEST_METHOD(PushBack)
-    {
-        til::some<int, 1> s;
-        s.push_back(12);
-        VERIFY_THROWS(s.push_back(12), std::out_of_range);
-    }
-
-    TEST_METHOD(PopBack)
-    {
-        til::some<int, 1> s;
-        VERIFY_THROWS(s.pop_back(), std::out_of_range);
-
-        s.push_back(12);
-        VERIFY_THROWS(s.push_back(12), std::out_of_range);
-    }
-
-    TEST_METHOD(Empty)
-    {
-        til::some<int, 2> s;
-        VERIFY_IS_TRUE(s.empty());
-        s.push_back(12);
-        VERIFY_IS_FALSE(s.empty());
-        s.pop_back();
-        VERIFY_IS_TRUE(s.empty());
-    }
-
-    TEST_METHOD(Clear)
-    {
-        til::some<int, 2> s;
-        VERIFY_IS_TRUE(s.empty());
-        s.push_back(12);
-        VERIFY_IS_FALSE(s.empty());
-        VERIFY_ARE_EQUAL(1u, s.size());
-        s.clear();
-        VERIFY_IS_TRUE(s.empty());
-        VERIFY_ARE_EQUAL(0u, s.size());
-    }
-
-    TEST_METHOD(ClearFreesMembers)
-    {
-        til::some<std::shared_ptr<int>, 2> s;
-
-        auto a = std::make_shared<int>(4);
-        auto weakA = std::weak_ptr<int>(a);
-
-        auto b = std::make_shared<int>(6);
-        auto weakB = std::weak_ptr<int>(b);
-
-        s.push_back(std::move(a));
-        s.push_back(std::move(b));
-
-        VERIFY_IS_FALSE(weakA.expired());
-        VERIFY_IS_FALSE(weakB.expired());
-
-        s.clear();
-
-        VERIFY_IS_TRUE(weakA.expired());
-        VERIFY_IS_TRUE(weakB.expired());
-    }
-
-    TEST_METHOD(Data)
-    {
-        til::some<int, 2> s;
-        const auto one = 1;
-        const auto two = 2;
-        s.push_back(one);
-        s.push_back(two);
-
-        auto data = s.data();
-
-        VERIFY_ARE_EQUAL(one, *data);
-        VERIFY_ARE_EQUAL(two, *(data + 1));
-    }
-
-    TEST_METHOD(FrontBack)
-    {
-        til::some<int, 2> s;
-        const auto one = 1;
-        const auto two = 2;
-        s.push_back(one);
-        s.push_back(two);
-
-        VERIFY_ARE_EQUAL(one, s.front());
-        VERIFY_ARE_EQUAL(two, s.back());
-    }
-
-    TEST_METHOD(Indexing)
-    {
-        const auto one = 14;
-        const auto two = 28;
-
-        til::some<int, 2> s;
-        VERIFY_THROWS(s.at(0), std::out_of_range);
-        VERIFY_THROWS(s.at(1), std::out_of_range);
-        auto a = s[0];
-        a = s[1];
-
-        s.push_back(one);
-        VERIFY_ARE_EQUAL(one, s.at(0));
-        VERIFY_ARE_EQUAL(one, s[0]);
-        VERIFY_THROWS(s.at(1), std::out_of_range);
-        a = s[1];
-
-        s.push_back(two);
-        VERIFY_ARE_EQUAL(one, s.at(0));
-        VERIFY_ARE_EQUAL(one, s[0]);
-        VERIFY_ARE_EQUAL(two, s.at(1));
-        VERIFY_ARE_EQUAL(two, s[1]);
-
-        s.pop_back();
-        VERIFY_ARE_EQUAL(one, s.at(0));
-        VERIFY_ARE_EQUAL(one, s[0]);
-        VERIFY_THROWS(s.at(1), std::out_of_range);
-        a = s[1];
-
-        s.pop_back();
-        VERIFY_THROWS(s.at(0), std::out_of_range);
-        VERIFY_THROWS(s.at(1), std::out_of_range);
-        a = s[0];
-        a = s[1];
-    }
-
-    TEST_METHOD(ForwardIter)
-    {
-        const int vals[] = { 17, 99 };
-        const int valLength = ARRAYSIZE(vals);
-
-        til::some<int, 2> s;
-        VERIFY_ARE_EQUAL(s.begin(), s.end());
-        VERIFY_ARE_EQUAL(s.cbegin(), s.cend());
-        VERIFY_ARE_EQUAL(s.begin(), s.cbegin());
-        VERIFY_ARE_EQUAL(s.end(), s.cend());
-
-        s.push_back(vals[0]);
-        s.push_back(vals[1]);
-
-        VERIFY_ARE_EQUAL(s.begin() + valLength, s.end());
-        VERIFY_ARE_EQUAL(s.cbegin() + valLength, s.cend());
-
-        auto count = 0;
-        for (const auto& i : s)
-        {
-            VERIFY_ARE_EQUAL(vals[count], i);
-            ++count;
-        }
-        VERIFY_ARE_EQUAL(valLength, count);
-
-        count = 0;
-        for (auto i = s.cbegin(); i < s.cend(); ++i)
-        {
-            VERIFY_ARE_EQUAL(vals[count], *i);
-            ++count;
-        }
-        VERIFY_ARE_EQUAL(valLength, count);
-
-        count = 0;
-        for (auto i = s.begin(); i < s.end(); ++i)
-        {
-            VERIFY_ARE_EQUAL(vals[count], *i);
-            ++count;
-        }
-        VERIFY_ARE_EQUAL(valLength, count);
-    }
-
-    TEST_METHOD(ReverseIter)
-    {
-        const int vals[] = { 17, 99 };
-        const int valLength = ARRAYSIZE(vals);
-
-        til::some<int, 2> s;
-        VERIFY_ARE_EQUAL(s.rbegin(), s.rend());
-        VERIFY_ARE_EQUAL(s.crbegin(), s.crend());
-        VERIFY_ARE_EQUAL(s.rbegin(), s.crbegin());
-        VERIFY_ARE_EQUAL(s.rend(), s.crend());
-
-        s.push_back(vals[0]);
-        s.push_back(vals[1]);
-
-        VERIFY_ARE_EQUAL(s.rbegin() + valLength, s.rend());
-        VERIFY_ARE_EQUAL(s.crbegin() + valLength, s.crend());
-
-        auto count = 0;
-        for (auto i = s.crbegin(); i < s.crend(); ++i)
-        {
-            VERIFY_ARE_EQUAL(vals[valLength - count - 1], *i);
-            ++count;
-        }
-        VERIFY_ARE_EQUAL(valLength, count);
-
-        count = 0;
-        for (auto i = s.rbegin(); i < s.rend(); ++i)
-        {
-            VERIFY_ARE_EQUAL(vals[valLength - count - 1], *i);
-            ++count;
-        }
-        VERIFY_ARE_EQUAL(valLength, count);
-    }
-};
diff --git a/src/til/ut_til/UnicodeTests.cpp b/src/til/ut_til/UnicodeTests.cpp
index 24d62beeaf6..e81d5b9a7a9 100644
--- a/src/til/ut_til/UnicodeTests.cpp
+++ b/src/til/ut_til/UnicodeTests.cpp
@@ -51,10 +51,10 @@ class UnicodeTests
         struct Test
         {
             std::wstring_view input;
-            til::some<std::wstring_view, 5> expected;
+            std::vector<std::wstring_view> expected;
         };
 
-        static constexpr std::array tests{
+        const std::array tests{
             Test{ L"", {} },
             Test{ L"a", { L"a" } },
             Test{ L"abc", { L"a", L"b", L"c" } },
diff --git a/src/til/ut_til/sources b/src/til/ut_til/sources
index ffe976d7cab..2e39e378a84 100644
--- a/src/til/ut_til/sources
+++ b/src/til/ut_til/sources
@@ -30,7 +30,6 @@ SOURCES = \
     RunLengthEncodingTests.cpp \
     SizeTests.cpp \
     SmallVectorTests.cpp \
-    SomeTests.cpp \
     StaticMapTests.cpp \
     string.cpp \
     u8u16convertTests.cpp \
diff --git a/src/til/ut_til/til.unit.tests.vcxproj b/src/til/ut_til/til.unit.tests.vcxproj
index 04694e68a16..d6b183d1282 100644
--- a/src/til/ut_til/til.unit.tests.vcxproj
+++ b/src/til/ut_til/til.unit.tests.vcxproj
@@ -32,7 +32,6 @@
     <ClCompile Include="RunLengthEncodingTests.cpp" />
     <ClCompile Include="SizeTests.cpp" />
     <ClCompile Include="SmallVectorTests.cpp" />
-    <ClCompile Include="SomeTests.cpp" />
     <ClCompile Include="SPSCTests.cpp" />
     <ClCompile Include="StaticMapTests.cpp" />
     <ClCompile Include="string.cpp" />
@@ -64,7 +63,6 @@
     <ClInclude Include="..\..\inc\til\rle.h" />
     <ClInclude Include="..\..\inc\til\size.h" />
     <ClInclude Include="..\..\inc\til\small_vector.h" />
-    <ClInclude Include="..\..\inc\til\some.h" />
     <ClInclude Include="..\..\inc\til\spsc.h" />
     <ClInclude Include="..\..\inc\til\static_map.h" />
     <ClInclude Include="..\..\inc\til\string.h" />
@@ -90,4 +88,4 @@
   <Import Project="$(SolutionDir)src\common.build.post.props" />
   <Import Project="$(SolutionDir)src\common.build.tests.props" />
   <Import Project="$(SolutionDir)src\common.nugetversions.targets" />
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/til/ut_til/til.unit.tests.vcxproj.filters b/src/til/ut_til/til.unit.tests.vcxproj.filters
index c25b0113980..15928ddb533 100644
--- a/src/til/ut_til/til.unit.tests.vcxproj.filters
+++ b/src/til/ut_til/til.unit.tests.vcxproj.filters
@@ -20,7 +20,6 @@
     <ClCompile Include="RunLengthEncodingTests.cpp" />
     <ClCompile Include="SizeTests.cpp" />
     <ClCompile Include="SmallVectorTests.cpp" />
-    <ClCompile Include="SomeTests.cpp" />
     <ClCompile Include="SPSCTests.cpp" />
     <ClCompile Include="StaticMapTests.cpp" />
     <ClCompile Include="string.cpp" />
@@ -96,9 +95,6 @@
     <ClInclude Include="..\..\inc\til\small_vector.h">
       <Filter>inc</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\inc\til\some.h">
-      <Filter>inc</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\inc\til\spsc.h">
       <Filter>inc</Filter>
     </ClInclude>
@@ -135,4 +131,4 @@
       <UniqueIdentifier>{7cf29ba4-d33d-4c3b-82e3-ab73e5a79685}</UniqueIdentifier>
     </Filter>
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/types/inc/IInputEvent.hpp b/src/types/inc/IInputEvent.hpp
index 4641c17332d..655acd8f9b7 100644
--- a/src/types/inc/IInputEvent.hpp
+++ b/src/types/inc/IInputEvent.hpp
@@ -3,8 +3,6 @@
 
 #pragma once
 
-#include <til/small_vector.h>
-
 #define ALT_PRESSED (RIGHT_ALT_PRESSED | LEFT_ALT_PRESSED)
 #define CTRL_PRESSED (RIGHT_CTRL_PRESSED | LEFT_CTRL_PRESSED)
 #define MOD_PRESSED (SHIFT_PRESSED | ALT_PRESSED | CTRL_PRESSED)
diff --git a/src/types/inc/viewport.hpp b/src/types/inc/viewport.hpp
index d762f64348f..b8b2029504e 100644
--- a/src/types/inc/viewport.hpp
+++ b/src/types/inc/viewport.hpp
@@ -17,7 +17,7 @@ namespace Microsoft::Console::Types
 {
     class Viewport;
 
-    using SomeViewports = til::some<Viewport, 4>;
+    using SomeViewports = til::small_vector<Viewport, 4>;
 
     class Viewport final
     {