dotnet-core/release-notes/3.0/api-diff/3.0.0_System.Reflection.md

System.Reflection

 namespace System.Reflection {
     public abstract class Assembly : ICustomAttributeProvider, ISerializable {
+        public virtual bool IsCollectible { get; }
     }
     public class CustomAttributeData {
-        public Type AttributeType { get; }
+        public virtual Type AttributeType { get; }
     }
-    public struct CustomAttributeNamedArgument
+    public readonly struct CustomAttributeNamedArgument
-    public struct CustomAttributeTypedArgument
+    public readonly struct CustomAttributeTypedArgument
+    public interface ICustomTypeProvider {
+        Type GetCustomType();
+    }
     public abstract class MemberInfo : ICustomAttributeProvider {
+        public virtual bool IsCollectible { get; }
     }
     public enum MethodImplAttributes {
+        AggressiveOptimization = 512,
     }
     public sealed class ReflectionTypeLoadException : SystemException, ISerializable {
+        public override string Message { get; }
+        public override string ToString();
     }
     public class TypeDelegator : TypeInfo {
+        public override bool IsCollectible { get; }
     }
     public abstract class TypeInfo : Type, IReflectableType {
+        protected TypeInfo();
     }
 }