Equals/GetHashCode for UnixDomainSocketEndPoint

[sakno]

Background and motivation

My network framework uses EndPoint class as abstraction layer to represent the peer address. It is easy to determine whether the two endpoints represent the same address using Equals method. However, UnixDomainSocketEndPoint doesn't override necessary methods in contrast to IPEndPoint and DnsEndPoint.

API Proposal

namespace System.Net.Sockets;

public sealed class UnixDomainSocketEndPoint : EndPoint
{
  public override bool Equals(object? other);
  public override int GetHashCode();
}

API Usage

var set = new HashSet();

set.Add(new UnixDomainSocketEndPoint("@abstract"));
set.Contains(new UnixDomainSocketEndPoint("@abstract"));

Alternative Designs

Implement custom equality logic:

static bool EndPointsAreEqual(EndPoint x, EndPoint y)
{
  if (x is UnixDomainSocketEndPoint uds1)
    return y is UnixDomainSocketEndPoint uds2 && string.Equals(uds1.ToString(), uds2.ToString(), StringComparison.Ordinal);

  return object.Equals(x, y);
}

Risks

Breaks behavior of default implementation of Equals and GetHashCode.

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Issue Details

---

Background and motivation

My network framework uses EndPoint class as abstraction layer to represent the peer address. It is easy to determine whether the two endpoints represent the same address using Equals method. However, UnixDomainSocketEndPoint doesn't override necessary methods in contrast to IPEndPoint and DnsEndPoint.

API Proposal

namespace System.Net.Sockets;

public sealed class UnixDomainSocketEndPoint : EndPoint
{
  public override bool Equals(object? other);
  public override int GetHashCode();
}

API Usage

var set = new HashSet();

set.Add(new UnixDomainSocketEndPoint("@abstract"));
set.Contains(new UnixDomainSocketEndPoint("@abstract"));

Alternative Designs

Implement custom equality logic:

static bool EndPointsAreEqual(EndPoint x, EndPoint y)
{
  if (x is UnixDomainSocketEndPoint uds1)
    return y is UnixDomainSocketEndPoint uds2 && string.Equals(uds1.ToString(), uds2.ToString(), StringComparison.Ordinal);

  return object.Equals(x, y);
}

Risks

Breaks behavior of default implementation of Equals and GetHashCode.

Author:	sakno
Assignees:	-
Labels:	api-suggestion, area-System.Net, untriaged
Milestone:	-

[stephentoub]

Given that both IPEndPoint and DnsEndPoint override these, it's reasonable for UnixDomainSocketEndPoint to as well. I don't think this really needs to be considered an API proposal. Technically it could break someone relying on Equals providing reference equality, but the chances of that are slim, especially since that's not what it means generally when using the base EndPoint.

[sakno]

@stephentoub , if so, I'm ready to make a PR.

[CarnaViire]

Triage: that makes sense; we would gladly accept the contribution @sakno
Moving to Future as it's not a priority

[sakno]

@CarnaViire , PR is ready for review.