[API Proposal]: MemoryExtension.Contains overload #135684

Background and motivation

I would like to check if a byte sequence contains another byte sequence.

Today I have to:

MemoryExtensions.IndexOf(myData, [(byte)1, (byte)1, (byte)1]) > -1 

There are Contains method overloads on MemoryExtensions, but no overload for a generic ReadOnlySpan<T> (there is a ReadOnlySpan<char> overload).

API Proposal

namespace System;

public partial class MemoryExtensions
{
+    public static unsafe bool Contains<T>(this ReadOnlySpan<T> span, ReadOnlySpan<T> value) where T : IEquatable<T>?
}

I presume the implementation will require unsafe.

API Usage

var myData = new byte[100];
Assert.NotEqual(-1, MemoryExtensions.IndexOf(myData, [(byte)0, (byte)3, (byte)101, (byte)102, (byte)103]));

to become:

var myData = new byte[100];
Assert.True(MemoryExtensions.Contains(myData, [(byte)0, (byte)3, (byte)101, (byte)102, (byte)103]));

Alternative Designs

No response

Risks

No response