From abe99a8dd4c2d9cf874111f7f1d1daddd6411d75 Mon Sep 17 00:00:00 2001
From: Anairkoen Schno <aaron.cirr.com@gmail.com>
Date: Mon, 23 Mar 2020 21:37:28 -0500
Subject: [PATCH] Added an additional helper extension

---
 IPA.Loader/Utilities/EnumerableExtensions.cs | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/IPA.Loader/Utilities/EnumerableExtensions.cs b/IPA.Loader/Utilities/EnumerableExtensions.cs
index 3605deac..fa2978dc 100644
--- a/IPA.Loader/Utilities/EnumerableExtensions.cs
+++ b/IPA.Loader/Utilities/EnumerableExtensions.cs
@@ -165,7 +165,7 @@ namespace IPA.Utilities
         }
 
         /// <summary>
-        /// LINQ extension method that filters <see langword="null"/> elements out of an enumeration.
+        /// LINQ-style extension method that filters <see langword="null"/> elements out of an enumeration.
         /// </summary>
         /// <typeparam name="T">the type of the enumeration</typeparam>
         /// <param name="self">the enumeration to filter</param>
@@ -174,7 +174,7 @@ namespace IPA.Utilities
             => self.Where(o => o != null);
 
         /// <summary>
-        /// LINQ extension method that filters <see langword="null"/> elements out of an enumeration based on a converter.
+        /// LINQ-style extension method that filters <see langword="null"/> elements out of an enumeration based on a converter.
         /// </summary>
         /// <typeparam name="T">the type of the enumeration</typeparam>
         /// <typeparam name="U">the type to compare to null</typeparam>
@@ -185,7 +185,7 @@ namespace IPA.Utilities
             => self.Where(o => pred(o) != null);
 
         /// <summary>
-        /// LINQ extension method that filters <see langword="null"/> elements from an enumeration of nullable types.
+        /// LINQ-style extension method that filters <see langword="null"/> elements from an enumeration of nullable types.
         /// </summary>
         /// <typeparam name="T">the underlying type of the nullable enumeration</typeparam>
         /// <param name="self">the enumeration to filter</param>
@@ -193,5 +193,15 @@ namespace IPA.Utilities
         public static IEnumerable<T> NonNull<T>(this IEnumerable<T?> self) where T : struct
             => self.Where(o => o != null).Select(o => o.Value);
 
+        /// <summary>
+        /// LINQ-style extension method that filters <see langword="null"/> elements out of an enumeration based on a converter to a nullable type.
+        /// </summary>
+        /// <typeparam name="T">the type of the enumeration</typeparam>
+        /// <typeparam name="U">the type of the predicate's resulting nullable</typeparam>
+        /// <param name="self">the enumeration to filter</param>
+        /// <param name="pred">the predicate to select for filtering</param>
+        /// <returns>a filtered enumerable</returns>
+        public static IEnumerable<T> NonNull<T, U>(this IEnumerable<T> self, Func<T, U?> pred) where U : struct
+            => self.Where(o => pred(o) != null);
     }
 }