HashSet.TryGetValue (#145)

api_list.include.md

@@ -15,6 +15,11 @@
  * `Boolean Remove<TKey, TValue>(TKey, TValue&)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.dictionary-2.remove)
 
 
+#### HashSet<T>
+
+ * `Boolean TryGetValue<T>(T, T&)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.hashset-1.trygetvalue)
+
+
 #### IEnumerable<TSource>
 
  * `IEnumerable<KeyValuePair<TKey,TAccumulate>> AggregateBy<TSource, TKey, TAccumulate>(Func<TSource,TKey>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>, IEqualityComparer<TKey>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.aggregateby#system-linq-enumerable-aggregateby-3(system-collections-generic-ienumerable((-0))-system-func((-0-1))-system-func((-1-2))-system-func((-2-0-2))-system-collections-generic-iequalitycomparer((-1))))

readme.md

@@ -372,6 +372,11 @@ The class `Polyfill` includes the following extension methods:
  * `Boolean Remove<TKey, TValue>(TKey, TValue&)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.dictionary-2.remove)
 
 
+#### HashSet<T>
+
+ * `Boolean TryGetValue<T>(T, T&)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.hashset-1.trygetvalue)
+
+
 #### IEnumerable<TSource>
 
  * `IEnumerable<KeyValuePair<TKey,TAccumulate>> AggregateBy<TSource, TKey, TAccumulate>(Func<TSource,TKey>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>, IEqualityComparer<TKey>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.aggregateby#system-linq-enumerable-aggregateby-3(system-collections-generic-ienumerable((-0))-system-func((-0-1))-system-func((-1-2))-system-func((-2-0-2))-system-collections-generic-iequalitycomparer((-1))))

src/Consume/Consume.cs

@@ -237,7 +237,6 @@ void SpanStartsWith()
         startsWith = "value".AsSpan().StartsWith("value", StringComparison.Ordinal);
     }
 
-
     void SpanEndsWith()
     {
         var result = "value".AsSpan().EndsWith("value");
@@ -263,6 +262,15 @@ void IsGenericMethodParameter()
         var result = typeof(string).IsGenericMethodParameter();
     }
 
+    void HashSetTryGetValue()
+    {
+        var set = new HashSet<string>
+        {
+            "value"
+        };
+        var found = set.TryGetValue("value", out var result);
+    }
+
     void HasSameMetadataDefinitionAs(MemberInfo info)
     {
         var result = info.HasSameMetadataDefinitionAs(info);

src/Polyfill/Polyfill_HashSet.cs

@@ -0,0 +1,42 @@
+// <auto-generated />
+
+#pragma warning disable
+
+#if NET46X || NET47  || NET471 || NETSTANDARD2_0
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using Link = System.ComponentModel.DescriptionAttribute;
+
+static partial class Polyfill
+{
+    /// <summary>
+    ///  Searches the set for a given value and returns the equal value it finds, if any.
+    /// </summary>
+    /// <param name="equalValue">The value to search for.</param>
+    /// <param name="actualValue">The value from the set that the search found, or the default value of T when the search yielded no match.</param>
+    /// <returns>A value indicating whether the search was successful.</returns>
+    [Link("https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.hashset-1.trygetvalue")]
+    public static bool TryGetValue<T>(
+        this HashSet<T> target,
+        T equalValue,
+        [MaybeNullWhen(false)] out T actualValue)
+    {
+        var comparer = target.Comparer;
+        var hashCode = comparer.GetHashCode(equalValue);
+        foreach (var item in target)
+        {
+            if (comparer.GetHashCode(item) == hashCode &&
+                comparer.Equals(item, equalValue))
+            {
+                actualValue = item;
+                return true;
+            }
+        }
+
+        actualValue = default;
+        return false;
+    }
+}
+#endif

src/Tests/PolyfillTests_HashSet.cs

@@ -0,0 +1,18 @@
+partial class PolyfillTests
+{
+    [Test]
+    public void TryGetValue()
+    {
+        var value = "value";
+        var set = new HashSet<string>
+        {
+            value
+        };
+        var found = set.TryGetValue("value", out var result);
+        Assert.True(found);
+        Assert.AreSame(value, result!);
+        found = set.TryGetValue("value2", out result);
+        Assert.Null(result);
+        Assert.False(found);
+    }
+}