Repository: dotnet/runtime
File: src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.CoreCLR.cs (C#)

Code before:
        /// <returns>The allocated memory.</returns>
        /// <exception cref="ArgumentException"><paramref name="type" /> must be a type provided by the runtime.</exception>
        /// <exception cref="ArgumentOutOfRangeException"><paramref name="size" /> is negative.</exception>
        public static IntPtr AllocateTypeAssociatedMemory(Type type, int size)
        {
            if (type is not RuntimeType)
            {
                throw new ArgumentException(SR.Arg_MustBeType, nameof(type));
            }

            ArgumentOutOfRangeException.ThrowIfNegative(size);

            return AllocateTypeAssociatedMemory(new QCallTypeHandle(ref rt), (uint)size);
        }

        /// <summary>Allocates aligned memory that's associated with the <paramref name="type" /> and is freed if and when the <see cref="Type" /> is unloaded.</summary>
        /// <param name="type">The type associated with the allocated memory.</param>
        /// <param name="size">The amount of memory to allocate, in bytes.</param>
        /// <param name="alignment">The alignment, in bytes, of the memory to allocate. This must be a power of <c>2</c>.</param>
        /// <returns>The allocated aligned memory.</returns>
        /// <exception cref="ArgumentException"><paramref name="type" /> must be a type provided by the runtime.</exception>
        /// <exception cref="ArgumentOutOfRangeException"><paramref name="size" /> is negative.</exception>
        /// <exception cref="ArgumentException"><paramref name="alignment" /> is not a power of <c>2</c>.</exception>
        public static IntPtr AllocateTypeAssociatedMemory(Type type, int size, int alignment)
        {
            if (type is not RuntimeType)
            {
                throw new ArgumentException(SR.Arg_MustBeType, nameof(type));
            }

            ArgumentOutOfRangeException.ThrowIfNegative(size);

            if (!BitOperations.IsPow2(alignment))
            {
                // The C standard doesn't define what a valid alignment is, however Windows and POSIX implementation requires a power of 2
                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_AlignmentMustBePow2);
            }

            return AlignedAllocateTypeAssociatedMemory(new QCallTypeHandle(ref rt), (uint)size, (uint)alignment);
        }

        [LibraryImport(QCall, EntryPoint = "RuntimeTypeHandle_AllocateTypeAssociatedMemory")]
        private static partial IntPtr AllocateTypeAssociatedMemory(QCallTypeHandle type, uint size);

        [LibraryImport(QCall, EntryPoint = "RuntimeTypeHandle_AlignedAllocateTypeAssociatedMemory")]
        private static partial IntPtr AlignedAllocateTypeAssociatedMemory(QCallTypeHandle type, uint size, uint alignment);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern unsafe TailCallArgBuffer* GetTailCallArgBuffer();

        [LibraryImport(QCall, EntryPoint = "TailCallHelp_AllocTailCallArgBufferInternal")]

Review comment (suggestion):
```suggestion
            if (type is not RuntimeType rt)
```

Code after:
        /// <returns>The allocated memory.</returns>
        /// <exception cref="ArgumentException"><paramref name="type" /> must be a type provided by the runtime.</exception>
        /// <exception cref="ArgumentOutOfRangeException"><paramref name="size" /> is negative.</exception>
        public static IntPtr AllocateTypeAssociatedMemory(Type type, int size)
        {
            if (type is not RuntimeType rt)
            {
                throw new ArgumentException(SR.Arg_MustBeType, nameof(type));
            }

            ArgumentOutOfRangeException.ThrowIfNegative(size);

            return AllocateTypeAssociatedMemory(new QCallTypeHandle(ref rt), (uint)size);
        }

        /// <summary>Allocates aligned memory that's associated with the <paramref name="type" /> and is freed if and when the <see cref="Type" /> is unloaded.</summary>
        /// <param name="type">The type associated with the allocated memory.</param>
        /// <param name="size">The amount of memory to allocate, in bytes.</param>
        /// <param name="alignment">The alignment, in bytes, of the memory to allocate. This must be a power of <c>2</c>.</param>
        /// <returns>The allocated aligned memory.</returns>
        /// <exception cref="ArgumentException"><paramref name="type" /> must be a type provided by the runtime.</exception>
        /// <exception cref="ArgumentOutOfRangeException"><paramref name="size" /> is negative.</exception>
        /// <exception cref="ArgumentException"><paramref name="alignment" /> is not a power of <c>2</c>.</exception>
        public static IntPtr AllocateTypeAssociatedMemory(Type type, int size, int alignment)
        {
            if (type is not RuntimeType rt)
            {
                throw new ArgumentException(SR.Arg_MustBeType, nameof(type));
            }

            ArgumentOutOfRangeException.ThrowIfNegative(size);

            if (!BitOperations.IsPow2(alignment))
            {
                // The C standard doesn't define what a valid alignment is, however Windows and POSIX implementation requires a power of 2
                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_AlignmentMustBePow2);
            }

            return AllocateTypeAssociatedMemoryAligned(new QCallTypeHandle(ref rt), (uint)size, (uint)alignment);
        }

        [LibraryImport(QCall, EntryPoint = "RuntimeTypeHandle_AllocateTypeAssociatedMemory")]
        private static partial IntPtr AllocateTypeAssociatedMemory(QCallTypeHandle type, uint size);

        [LibraryImport(QCall, EntryPoint = "RuntimeTypeHandle_AllocateTypeAssociatedMemoryAligned")]
        private static partial IntPtr AllocateTypeAssociatedMemoryAligned(QCallTypeHandle type, uint size, uint alignment);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern unsafe TailCallArgBuffer* GetTailCallArgBuffer();

        [LibraryImport(QCall, EntryPoint = "TailCallHelp_AllocTailCallArgBufferInternal")]