Generic math for UnitsNet in .NET 7

CodeGen/Generators/UnitsNetGen/QuantityGenerator.cs

@@ -64,7 +64,7 @@ namespace UnitsNet
             Writer.WLIfText(1, GetObsoleteAttributeOrNull(_quantity));
             Writer.W(@$"
     [DataContract]
-    public readonly partial struct {_quantity.Name} : IQuantity<{_unitEnumName}>, ");
+    public readonly partial struct {_quantity.Name} : {(_quantity.GenerateArithmetic ? "IArithmeticQuantity" : "IQuantity")}<{_quantity.Name}, {_unitEnumName}, {_quantity.ValueType}>, ");
             if (_quantity.ValueType == "decimal")
             {
                 Writer.W("IDecimalQuantity, ");
@@ -239,9 +239,19 @@ private void GenerateStaticProperties()
         ///     Gets an instance of this quantity with a value of 0 in the base unit {_quantity.BaseUnit}.
         /// </summary>
         public static {_quantity.Name} Zero {{ get; }}
+");
 
-        #endregion
+            if (_quantity.GenerateArithmetic)
+            {
+                Writer.WL($@"
+        /// <inheritdoc cref=""Zero""/>
+        public static {_quantity.Name} AdditiveIdentity => Zero;
 ");
+            }
+
+            Writer.WL($@"
+        #endregion
+ ");
         }
 
         private void GenerateProperties()

UnitsNet.Tests/GenericMathExtensionsTests.cs

@@ -0,0 +1,37 @@
+// Licensed under MIT No Attribution, see LICENSE file at the root.
+// Copyright 2013 Andreas Gullberg Larsen (andreas.larsen84@gmail.com). Maintained at https://github.com/angularsen/UnitsNet.
+
+#if NET7_0_OR_GREATER
+using UnitsNet.GenericMath;
+using Xunit;
+
+namespace UnitsNet.Tests;
+
+public class GenericMathExtensionsTests
+{
+    [Fact]
+    public void CanCalcSum()
+    {
+        Length[] values = { Length.FromCentimeters(100), Length.FromCentimeters(200) };
+
+        Assert.Equal(Length.FromCentimeters(300), values.Sum());
+    }
+
+    [Fact]
+    public void CanCalcAverage_ForQuantitiesWithDoubleValueType()
+    {
+        Length[] values = { Length.FromCentimeters(100), Length.FromCentimeters(200) };
+
+        Assert.Equal(Length.FromCentimeters(150), values.Average());
+    }
+
+    [Fact]
+    public void CanCalcAverage_ForQuantitiesWithDecimalValueType()
+    {
+        Information[] values = { Information.FromBytes(100), Information.FromBytes(200) };
+
+        Assert.Equal(Information.FromBytes(150), values.Average());
+    }
+}
+
+#endif

UnitsNet.Tests/UnitsNet.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net6.0;net48</TargetFrameworks>
+    <TargetFrameworks>net7.0;net48</TargetFrameworks>
     <LangVersion>latest</LangVersion>
     <IsTestProject>true</IsTestProject>
     <NoWarn>CS0618</NoWarn>