KeyValuePair implementation using C♯ 6 features

KeyValuePair`2.cs

using System;

public struct KeyValuePair<TKey, TValue> : IEquatable<KeyValuePair<TKey, TValue>>
{
    public KeyValuePair(TKey key, TValue value)
    {
        Key = key;
        Value = value;
    }

    public TKey Key { get; }

    public TValue Value { get; }

    public static bool operator ==(KeyValuePair<TKey, TValue> left, KeyValuePair<TKey, TValue> right) => Equals(left, right);

    public static bool operator !=(KeyValuePair<TKey, TValue> left, KeyValuePair<TKey, TValue> right) => !Equals(left, right);

    public override bool Equals(object obj) => obj is KeyValuePair<TKey, TValue> && Equals((KeyValuePair<TKey, TValue>)obj);

    public bool Equals(KeyValuePair<TKey, TValue> other) => Equals(Key, other.Key) && Equals(Value, other.Value);

    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 13;
            hash = (hash * 7) + Key?.GetHashCode() ?? 0;
            hash = (hash * 7) + Value?.GetHashCode() ?? 0;
            return hash;
        }
    }

    public override string ToString() => $"[{Key?.ToString()}, {Value?.ToString()}]";
}