diff --git a/src/libraries/System.Private.CoreLib/src/System/ValueTuple.cs b/src/libraries/System.Private.CoreLib/src/System/ValueTuple.cs
index 240ad862ffcf2..87f5cd3897707 100644
--- a/src/libraries/System.Private.CoreLib/src/System/ValueTuple.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/ValueTuple.cs
@@ -31,7 +31,7 @@ internal interface IValueTupleInternal : ITuple
     /// </summary>
     [Serializable]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct ValueTuple
+    public readonly struct ValueTuple
         : IEquatable<ValueTuple>, IStructuralEquatable, IStructuralComparable, IComparable, IComparable<ValueTuple>, IValueTupleInternal, ITuple
     {
         /// <summary>
@@ -290,7 +290,7 @@ public ValueTuple(T1 item1)
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1> tuple && Equals(tuple);
         }
@@ -305,16 +305,16 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its field
         /// is equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1> other)
+        public readonly bool Equals(ValueTuple<T1> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1> vt &&
             comparer.Equals(Item1, vt.Item1);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -337,12 +337,12 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1> other)
+        public readonly int CompareTo(ValueTuple<T1> other)
         {
             return Comparer<T1>.Default.Compare(Item1, other.Item1);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -366,12 +366,12 @@ public override int GetHashCode()
             return Item1?.GetHashCode() ?? 0;
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return comparer.GetHashCode(Item1!);
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return comparer.GetHashCode(Item1!);
         }
@@ -398,12 +398,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 1;
+        readonly int ITuple.Length => 1;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index]
+        readonly object? ITuple.this[int index]
         {
             get
             {
@@ -462,7 +462,7 @@ public ValueTuple(T1 item1, T2 item2)
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2> tuple && Equals(tuple);
         }
@@ -476,7 +476,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2> other)
+        public readonly bool Equals(ValueTuple<T1, T2> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2);
@@ -500,12 +500,12 @@ public bool Equals(ValueTuple<T1, T2> other)
         ///  <see cref="IEqualityComparer.Equals"/> implementation. If this method call returns <see langword="true"/>, the method is
         ///  called again and passed the <see cref="Item2"/> values of the two <see cref="ValueTuple{T1, T2}"/> instances.
         /// </remarks>
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -528,7 +528,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2> other)
+        public readonly int CompareTo(ValueTuple<T1, T2> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -536,7 +536,7 @@ public int CompareTo(ValueTuple<T1, T2> other)
             return Comparer<T2>.Default.Compare(Item2, other.Item2);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -564,18 +564,18 @@ public override int GetHashCode()
                                     Item2?.GetHashCode() ?? 0);
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             return HashCode.Combine(comparer.GetHashCode(Item1!),
                                     comparer.GetHashCode(Item2!));
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -603,12 +603,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 2;
+        readonly int ITuple.Length => 2;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index] =>
+        readonly object? ITuple.this[int index] =>
             index switch
             {
                 0 => Item1,
@@ -668,7 +668,7 @@ public ValueTuple(T1 item1, T2 item2, T3 item3)
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2, T3> tuple && Equals(tuple);
         }
@@ -683,20 +683,20 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2, T3> other)
+        public readonly bool Equals(ValueTuple<T1, T2, T3> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2)
                 && EqualityComparer<T3>.Default.Equals(Item3, other.Item3);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2, T3> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2) &&
             comparer.Equals(Item3, vt.Item3);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -719,7 +719,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2, T3> other)
+        public readonly int CompareTo(ValueTuple<T1, T2, T3> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -730,7 +730,7 @@ public int CompareTo(ValueTuple<T1, T2, T3> other)
             return Comparer<T3>.Default.Compare(Item3, other.Item3);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -762,19 +762,19 @@ public override int GetHashCode()
                                     Item3?.GetHashCode() ?? 0);
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             return HashCode.Combine(comparer.GetHashCode(Item1!),
                                     comparer.GetHashCode(Item2!),
                                     comparer.GetHashCode(Item3!));
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -800,12 +800,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 3;
+        readonly int ITuple.Length => 3;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index] =>
+        readonly object? ITuple.this[int index] =>
             index switch
             {
                 0 => Item1,
@@ -873,7 +873,7 @@ public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4)
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2, T3, T4> tuple && Equals(tuple);
         }
@@ -888,7 +888,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2, T3, T4> other)
+        public readonly bool Equals(ValueTuple<T1, T2, T3, T4> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2)
@@ -896,14 +896,14 @@ public bool Equals(ValueTuple<T1, T2, T3, T4> other)
                 && EqualityComparer<T4>.Default.Equals(Item4, other.Item4);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2, T3, T4> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2) &&
             comparer.Equals(Item3, vt.Item3) &&
             comparer.Equals(Item4, vt.Item4);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -926,7 +926,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2, T3, T4> other)
+        public readonly int CompareTo(ValueTuple<T1, T2, T3, T4> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -940,7 +940,7 @@ public int CompareTo(ValueTuple<T1, T2, T3, T4> other)
             return Comparer<T4>.Default.Compare(Item4, other.Item4);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -976,12 +976,12 @@ public override int GetHashCode()
                                     Item4?.GetHashCode() ?? 0);
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             return HashCode.Combine(comparer.GetHashCode(Item1!),
                                     comparer.GetHashCode(Item2!),
@@ -989,7 +989,7 @@ private int GetHashCodeCore(IEqualityComparer comparer)
                                     comparer.GetHashCode(Item4!));
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -1015,12 +1015,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 4;
+        readonly int ITuple.Length => 4;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index] =>
+        readonly object? ITuple.this[int index] =>
             index switch
             {
                 0 => Item1,
@@ -1096,7 +1096,7 @@ public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5)
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2, T3, T4, T5> tuple && Equals(tuple);
         }
@@ -1111,7 +1111,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2, T3, T4, T5> other)
+        public readonly bool Equals(ValueTuple<T1, T2, T3, T4, T5> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2)
@@ -1120,14 +1120,14 @@ public bool Equals(ValueTuple<T1, T2, T3, T4, T5> other)
                 && EqualityComparer<T5>.Default.Equals(Item5, other.Item5);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2, T3, T4, T5> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2) &&
             comparer.Equals(Item3, vt.Item3) &&
             comparer.Equals(Item5, vt.Item5);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -1150,7 +1150,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2, T3, T4, T5> other)
+        public readonly int CompareTo(ValueTuple<T1, T2, T3, T4, T5> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -1167,7 +1167,7 @@ public int CompareTo(ValueTuple<T1, T2, T3, T4, T5> other)
             return Comparer<T5>.Default.Compare(Item5, other.Item5);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -1207,12 +1207,12 @@ public override int GetHashCode()
                                     Item5?.GetHashCode() ?? 0);
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             return HashCode.Combine(comparer.GetHashCode(Item1!),
                                     comparer.GetHashCode(Item2!),
@@ -1221,7 +1221,7 @@ private int GetHashCodeCore(IEqualityComparer comparer)
                                     comparer.GetHashCode(Item5!));
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -1247,12 +1247,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 5;
+        readonly int ITuple.Length => 5;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index] =>
+        readonly object? ITuple.this[int index] =>
             index switch
             {
                 0 => Item1,
@@ -1336,7 +1336,7 @@ public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6)
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2, T3, T4, T5, T6> tuple && Equals(tuple);
         }
@@ -1351,7 +1351,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6> other)
+        public readonly bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2)
@@ -1361,7 +1361,7 @@ public bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6> other)
                 && EqualityComparer<T6>.Default.Equals(Item6, other.Item6);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2, T3, T4, T5, T6> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2) &&
@@ -1369,7 +1369,7 @@ other is ValueTuple<T1, T2, T3, T4, T5, T6> vt &&
             comparer.Equals(Item5, vt.Item5) &&
             comparer.Equals(Item6, vt.Item6);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -1392,7 +1392,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6> other)
+        public readonly int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -1412,7 +1412,7 @@ public int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6> other)
             return Comparer<T6>.Default.Compare(Item6, other.Item6);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -1456,12 +1456,12 @@ public override int GetHashCode()
                                     Item6?.GetHashCode() ?? 0);
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             return HashCode.Combine(comparer.GetHashCode(Item1!),
                                     comparer.GetHashCode(Item2!),
@@ -1471,7 +1471,7 @@ private int GetHashCodeCore(IEqualityComparer comparer)
                                     comparer.GetHashCode(Item6!));
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -1497,12 +1497,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 6;
+        readonly int ITuple.Length => 6;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index] =>
+        readonly object? ITuple.this[int index] =>
             index switch
             {
                 0 => Item1,
@@ -1594,7 +1594,7 @@ public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2, T3, T4, T5, T6, T7> tuple && Equals(tuple);
         }
@@ -1609,7 +1609,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6, T7> other)
+        public readonly bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6, T7> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2)
@@ -1620,7 +1620,7 @@ public bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6, T7> other)
                 && EqualityComparer<T7>.Default.Equals(Item7, other.Item7);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2, T3, T4, T5, T6, T7> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2) &&
@@ -1629,7 +1629,7 @@ other is ValueTuple<T1, T2, T3, T4, T5, T6, T7> vt &&
             comparer.Equals(Item6, vt.Item6) &&
             comparer.Equals(Item7, vt.Item7);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -1652,7 +1652,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6, T7> other)
+        public readonly int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6, T7> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -1675,7 +1675,7 @@ public int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6, T7> other)
             return Comparer<T7>.Default.Compare(Item7, other.Item7);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -1723,12 +1723,12 @@ public override int GetHashCode()
                                     Item7?.GetHashCode() ?? 0);
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             return HashCode.Combine(comparer.GetHashCode(Item1!),
                                     comparer.GetHashCode(Item2!),
@@ -1739,7 +1739,7 @@ private int GetHashCodeCore(IEqualityComparer comparer)
                                     comparer.GetHashCode(Item7!));
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -1765,12 +1765,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => 7;
+        readonly int ITuple.Length => 7;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index] =>
+        readonly object? ITuple.this[int index] =>
             index switch
             {
                 0 => Item1,
@@ -1876,7 +1876,7 @@ public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7
         ///     <item><description>Its components are equal to those of the current instance. Equality is determined by the default object equality comparer for each component.</description></item>
         /// </list>
         /// </remarks>
-        public override bool Equals([NotNullWhen(true)] object? obj)
+        public override readonly bool Equals([NotNullWhen(true)] object? obj)
         {
             return obj is ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> tuple && Equals(tuple);
         }
@@ -1891,7 +1891,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
         /// The <paramref name="other"/> parameter is considered to be equal to the current instance if each of its fields
         /// are equal to that of the current instance, using the default comparer for that field's type.
         /// </remarks>
-        public bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other)
+        public readonly bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other)
         {
             return EqualityComparer<T1>.Default.Equals(Item1, other.Item1)
                 && EqualityComparer<T2>.Default.Equals(Item2, other.Item2)
@@ -1903,7 +1903,7 @@ public bool Equals(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other)
                 && EqualityComparer<TRest>.Default.Equals(Rest, other.Rest);
         }
 
-        bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
+        readonly bool IStructuralEquatable.Equals(object? other, IEqualityComparer comparer) =>
             other is ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> vt &&
             comparer.Equals(Item1, vt.Item1) &&
             comparer.Equals(Item2, vt.Item2) &&
@@ -1913,7 +1913,7 @@ other is ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> vt &&
             comparer.Equals(Item7, vt.Item7) &&
             comparer.Equals(Rest, vt.Rest);
 
-        int IComparable.CompareTo(object? other)
+        readonly int IComparable.CompareTo(object? other)
         {
             if (other is not null)
             {
@@ -1936,7 +1936,7 @@ int IComparable.CompareTo(object? other)
         /// instance is equal to <paramref name="other"/>, and greater than zero if this instance is greater
         /// than <paramref name="other"/>.
         /// </returns>
-        public int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other)
+        public readonly int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other)
         {
             int c = Comparer<T1>.Default.Compare(Item1, other.Item1);
             if (c != 0) return c;
@@ -1962,7 +1962,7 @@ public int CompareTo(ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other)
             return Comparer<TRest>.Default.Compare(Rest, other.Rest);
         }
 
-        int IStructuralComparable.CompareTo(object? other, IComparer comparer)
+        readonly int IStructuralComparable.CompareTo(object? other, IComparer comparer)
         {
             if (other is not null)
             {
@@ -2076,12 +2076,12 @@ public override int GetHashCode()
             return -1;
         }
 
-        int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
+        readonly int IStructuralEquatable.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
 
-        private int GetHashCodeCore(IEqualityComparer comparer)
+        private readonly int GetHashCodeCore(IEqualityComparer comparer)
         {
             // We want to have a limited hash in this case. We'll use the first 7 elements of the tuple
             if (Rest is not IValueTupleInternal rest)
@@ -2151,7 +2151,7 @@ private int GetHashCodeCore(IEqualityComparer comparer)
             return -1;
         }
 
-        int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
+        readonly int IValueTupleInternal.GetHashCode(IEqualityComparer comparer)
         {
             return GetHashCodeCore(comparer);
         }
@@ -2187,12 +2187,12 @@ string IValueTupleInternal.ToStringEnd()
         /// <summary>
         /// The number of positions in this data structure.
         /// </summary>
-        int ITuple.Length => Rest is IValueTupleInternal ? 7 + ((IValueTupleInternal)Rest).Length : 8;
+        readonly int ITuple.Length => Rest is IValueTupleInternal ? 7 + ((IValueTupleInternal)Rest).Length : 8;
 
         /// <summary>
         /// Get the element at position <param name="index"/>.
         /// </summary>
-        object? ITuple.this[int index]
+        readonly object? ITuple.this[int index]
         {
             get
             {
diff --git a/src/libraries/System.Runtime/ref/System.Runtime.cs b/src/libraries/System.Runtime/ref/System.Runtime.cs
index 900040db349ef..1b4994a2ec51a 100644
--- a/src/libraries/System.Runtime/ref/System.Runtime.cs
+++ b/src/libraries/System.Runtime/ref/System.Runtime.cs
@@ -7113,7 +7113,7 @@ public UnhandledExceptionEventArgs(object exception, bool isTerminating) { }
         public bool IsTerminating { get { throw null; } }
     }
     public delegate void UnhandledExceptionEventHandler(object sender, System.UnhandledExceptionEventArgs e);
-    public partial struct ValueTuple : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple>, System.IEquatable<System.ValueTuple>, System.Runtime.CompilerServices.ITuple
+    public readonly partial struct ValueTuple : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple>, System.IEquatable<System.ValueTuple>, System.Runtime.CompilerServices.ITuple
     {
         object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
         int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
@@ -7140,16 +7140,16 @@ public partial struct ValueTuple<T1> : System.Collections.IStructuralComparable,
     {
         public T1 Item1;
         public ValueTuple(T1 item1) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo(System.ValueTuple<T1> other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals(System.ValueTuple<T1> other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo(System.ValueTuple<T1> other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals(System.ValueTuple<T1> other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<(T1, T2)>, System.IEquatable<(T1, T2)>, System.Runtime.CompilerServices.ITuple
@@ -7157,16 +7157,16 @@ public partial struct ValueTuple<T1, T2> : System.Collections.IStructuralCompara
         public T1 Item1;
         public T2 Item2;
         public ValueTuple(T1 item1, T2 item2) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo((T1, T2) other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals((T1, T2) other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo((T1, T2) other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals((T1, T2) other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2, T3> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<(T1, T2, T3)>, System.IEquatable<(T1, T2, T3)>, System.Runtime.CompilerServices.ITuple
@@ -7175,16 +7175,16 @@ public partial struct ValueTuple<T1, T2, T3> : System.Collections.IStructuralCom
         public T2 Item2;
         public T3 Item3;
         public ValueTuple(T1 item1, T2 item2, T3 item3) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo((T1, T2, T3) other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals((T1, T2, T3) other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo((T1, T2, T3) other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals((T1, T2, T3) other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2, T3, T4> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<(T1, T2, T3, T4)>, System.IEquatable<(T1, T2, T3, T4)>, System.Runtime.CompilerServices.ITuple
@@ -7194,16 +7194,16 @@ public partial struct ValueTuple<T1, T2, T3, T4> : System.Collections.IStructura
         public T3 Item3;
         public T4 Item4;
         public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo((T1, T2, T3, T4) other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals((T1, T2, T3, T4) other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo((T1, T2, T3, T4) other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals((T1, T2, T3, T4) other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2, T3, T4, T5> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<(T1, T2, T3, T4, T5)>, System.IEquatable<(T1, T2, T3, T4, T5)>, System.Runtime.CompilerServices.ITuple
@@ -7214,16 +7214,16 @@ public partial struct ValueTuple<T1, T2, T3, T4, T5> : System.Collections.IStruc
         public T4 Item4;
         public T5 Item5;
         public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo((T1, T2, T3, T4, T5) other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals((T1, T2, T3, T4, T5) other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo((T1, T2, T3, T4, T5) other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals((T1, T2, T3, T4, T5) other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2, T3, T4, T5, T6> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<(T1, T2, T3, T4, T5, T6)>, System.IEquatable<(T1, T2, T3, T4, T5, T6)>, System.Runtime.CompilerServices.ITuple
@@ -7235,16 +7235,16 @@ public partial struct ValueTuple<T1, T2, T3, T4, T5, T6> : System.Collections.IS
         public T5 Item5;
         public T6 Item6;
         public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo((T1, T2, T3, T4, T5, T6) other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals((T1, T2, T3, T4, T5, T6) other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo((T1, T2, T3, T4, T5, T6) other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals((T1, T2, T3, T4, T5, T6) other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2, T3, T4, T5, T6, T7> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<(T1, T2, T3, T4, T5, T6, T7)>, System.IEquatable<(T1, T2, T3, T4, T5, T6, T7)>, System.Runtime.CompilerServices.ITuple
@@ -7257,16 +7257,16 @@ public partial struct ValueTuple<T1, T2, T3, T4, T5, T6, T7> : System.Collection
         public T6 Item6;
         public T7 Item7;
         public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo((T1, T2, T3, T4, T5, T6, T7) other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals((T1, T2, T3, T4, T5, T6, T7) other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo((T1, T2, T3, T4, T5, T6, T7) other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals((T1, T2, T3, T4, T5, T6, T7) other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public partial struct ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> : System.Collections.IStructuralComparable, System.Collections.IStructuralEquatable, System.IComparable, System.IComparable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>>, System.IEquatable<System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>>, System.Runtime.CompilerServices.ITuple where TRest : struct
@@ -7280,16 +7280,16 @@ public partial struct ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> : System.Col
         public T7 Item7;
         public TRest Rest;
         public ValueTuple(T1 item1, T2 item2, T3 item3, T4 item4, T5 item5, T6 item6, T7 item7, TRest rest) { throw null; }
-        object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
-        int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
-        public int CompareTo(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other) { throw null; }
-        public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
-        public bool Equals(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other) { throw null; }
+        readonly object? System.Runtime.CompilerServices.ITuple.this[int index] { get { throw null; } }
+        readonly int System.Runtime.CompilerServices.ITuple.Length { get { throw null; } }
+        public readonly int CompareTo(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other) { throw null; }
+        public override readonly bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
+        public readonly bool Equals(System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest> other) { throw null; }
         public override int GetHashCode() { throw null; }
-        int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
-        bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
-        int System.IComparable.CompareTo(object? other) { throw null; }
+        readonly int System.Collections.IStructuralComparable.CompareTo(object? other, System.Collections.IComparer comparer) { throw null; }
+        readonly bool System.Collections.IStructuralEquatable.Equals(object? other, System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.Collections.IStructuralEquatable.GetHashCode(System.Collections.IEqualityComparer comparer) { throw null; }
+        readonly int System.IComparable.CompareTo(object? other) { throw null; }
         public override string ToString() { throw null; }
     }
     public abstract partial class ValueType