Revert IQuantity.UnitInfo DIM in favor of GetUnitInfo() extension on all TFMs

Reverts the default interface members added in #1649 and instead exposes
GetUnitInfo() / GetUnitInfo<TUnit>() as extension methods on all target
frameworks (previously gated behind #if !NET).

Rationale (per @lipchev review feedback on #1649):
- DIM bloats the IQuantity contract with members that just delegate to
  QuantityInfo[UnitKey]; aim is a leaner interface.
- A custom IQuantity implementor overriding UnitInfo would silently
  diverge from internal lookups (UnitConverter, UnitAbbreviationsCache
  etc.) which always go through QuantityInfo, not the new property.
- Calling the DIM through the IQuantity interface on a struct quantity
  causes interface dispatch and boxing per call.

The extension method has none of these issues and gives the same
ergonomic call-site (quantity.GetUnitInfo()) on every TFM.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: angularsen

UnitsNet.Tests/CustomCode/IQuantityTests.cs

@@ -60,44 +60,44 @@ public void ToUnit_UnitSystem_ThrowsArgumentNullExceptionIfNull()
     }
 
     [Fact]
-    public void UnitInfo_ReturnsUnitInfoForQuantityUnit()
+    public void GetUnitInfo_ReturnsUnitInfoForQuantityUnit()
     {
         var length = new Length(3.0, LengthUnit.Centimeter);
         IQuantity quantity = length;
 
-        UnitInfo unitInfo = quantity.UnitInfo;
+        UnitInfo unitInfo = quantity.GetUnitInfo();
 
         Assert.Equal(nameof(LengthUnit.Centimeter), unitInfo.Name);
         Assert.Equal(quantity.UnitKey, unitInfo.UnitKey);
     }
 
     [Fact]
-    public void UnitInfo_Zero_ReturnsBaseUnitInfo()
+    public void GetUnitInfo_Zero_ReturnsBaseUnitInfo()
     {
         IQuantity quantity = Length.Info.Zero;
 
-        UnitInfo unitInfo = quantity.UnitInfo;
+        UnitInfo unitInfo = quantity.GetUnitInfo();
 
         Assert.Equal(Length.Info.BaseUnitInfo.UnitKey, unitInfo.UnitKey);
     }
 
     [Fact]
-    public void UnitInfo_TypedQuantity_ReturnsTypedUnitInfo()
+    public void GetUnitInfo_TypedQuantity_ReturnsTypedUnitInfo()
     {
         IQuantity<LengthUnit> quantity = new Length(3.0, LengthUnit.Centimeter);
 
-        UnitInfo<LengthUnit> unitInfo = quantity.UnitInfo;
+        UnitInfo<LengthUnit> unitInfo = quantity.GetUnitInfo();
 
         Assert.Equal(LengthUnit.Centimeter, unitInfo.Value);
         Assert.Equal(nameof(LengthUnit.Centimeter), unitInfo.Name);
     }
 
     [Fact]
-    public void UnitInfo_MatchesUnit()
+    public void GetUnitInfo_MatchesUnit()
     {
         Assert.All(Quantity.Infos.Select(x => x.Zero), quantity =>
         {
-            Assert.Equal(quantity.Unit, quantity.UnitInfo.Value);
+            Assert.Equal(quantity.Unit, quantity.GetUnitInfo().Value);
         });
     }
 

UnitsNet/Extensions/QuantityExtensions.cs

@@ -11,16 +11,11 @@ namespace UnitsNet;
 /// </summary>
 public static class QuantityExtensions
 {
-#if !NET
     /// <summary>
     ///     Gets the <see cref="UnitInfo"/> for the unit this quantity was constructed with.
     /// </summary>
     /// <param name="quantity">The quantity.</param>
     /// <returns>The <see cref="UnitInfo"/> for the quantity's unit.</returns>
-    /// <remarks>
-    ///     On .NET 5+ targets, this is available as a default interface member property
-    ///     <c>IQuantity.UnitInfo</c> instead.
-    /// </remarks>
     public static UnitInfo GetUnitInfo(this IQuantity quantity)
     {
         return quantity.QuantityInfo[quantity.UnitKey];
@@ -32,16 +27,11 @@ public static UnitInfo GetUnitInfo(this IQuantity quantity)
     /// <typeparam name="TUnit">The unit enum type.</typeparam>
     /// <param name="quantity">The quantity.</param>
     /// <returns>The <see cref="UnitInfo{TUnit}"/> for the quantity's unit.</returns>
-    /// <remarks>
-    ///     On .NET 5+ targets, this is available as a default interface member property
-    ///     <c>IQuantity&lt;TUnitType&gt;.UnitInfo</c> instead.
-    /// </remarks>
     public static UnitInfo<TUnit> GetUnitInfo<TUnit>(this IQuantity<TUnit> quantity)
         where TUnit : struct, Enum
     {
         return quantity.QuantityInfo[quantity.Unit];
     }
-#endif
 
     /// <inheritdoc cref="IQuantity.As(UnitKey)" />
     /// <remarks>This should be using UnitConverter.Default.ConvertValue(quantity, toUnit) </remarks>

UnitsNet/IQuantity.cs

@@ -58,17 +58,6 @@ public interface IQuantity : IFormattable
         ///     as it avoids the boxing that would normally occur when casting the enum to <see cref="Enum" />.
         /// </remarks>
         UnitKey UnitKey { get; }
-
-#if NET
-        /// <summary>
-        ///     Gets the <see cref="UnitsNet.UnitInfo"/> for the unit this quantity was constructed with.
-        /// </summary>
-        /// <remarks>
-        ///     On targets that do not support default interface members (e.g. netstandard2.0),
-        ///     use the <c>GetUnitInfo()</c> extension method from <see cref="QuantityExtensions"/> instead.
-        /// </remarks>
-        UnitInfo UnitInfo => QuantityInfo[UnitKey];
-#endif
     }
 
     /// <summary>
@@ -105,13 +94,8 @@ public interface IQuantity<TUnitType> : IQuantity
 
 #if NET
 
-        /// <inheritdoc cref="IQuantity.UnitInfo"/>
-        new UnitInfo<TUnitType> UnitInfo => QuantityInfo[Unit];
-
         #region Implementation of IQuantity
 
-        UnitInfo IQuantity.UnitInfo => UnitInfo;
-
         QuantityInfo IQuantity.QuantityInfo
         {
             get => QuantityInfo;