Use C# 7.3 Enum constraints.

HISTORY.md

@@ -1,5 +1,6 @@
 ## v22.1.1
 * PR 144: Argument support for mustache handlebars. Example: `{{name.firstname(Male)}}`
+* Using **C# 7.3** generic `Enum` constraints for methods that only accept enums. Example: `f.PickRandom<Enum>()`.
 
 ## v22.0.9
 * Issue 143: Fixed rare case when `f.IndexGlobal` could be zero twice at start of generation.

Source/Bogus/Bogus.csproj

@@ -6,7 +6,7 @@
     <Version>0.0.0-localbuild</Version>
     <Authors>Brian Chavez</Authors>
     <TargetFrameworks>net40;netstandard1.3;netstandard2.0</TargetFrameworks>
-    <LangVersion>latest</LangVersion>
+    <LangVersion>7.3</LangVersion>
     <CodeAnalysisRuleSet>Bogus.ruleset</CodeAnalysisRuleSet>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyOriginatorKeyFile>

Source/Bogus/Faker.cs

@@ -292,7 +292,7 @@ public IEnumerable<T> MakeLazy<T>(int count, Func<int, T> action)
       /// Picks a random Enum of T. Works only with Enums.
       /// </summary>
       /// <typeparam name="T">Must be an Enum</typeparam>
-      public T PickRandom<T>() where T : struct
+      public T PickRandom<T>() where T : struct, Enum
       {
          return this.Random.Enum<T>();
       }
@@ -301,7 +301,7 @@ public IEnumerable<T> MakeLazy<T>(int count, Func<int, T> action)
       /// Picks a random Enum of T, excluding those passed as parameters.
       /// </summary>
       /// <param name="exclude">The items in the Enum of T to exclude from selection.</param>
-      public T PickRandomWithout<T>(params T[] exclude) where T : struct
+      public T PickRandomWithout<T>(params T[] exclude) where T : struct, Enum
       {
          return this.Random.Enum(exclude);
       }

Source/Bogus/Randomizer.cs

@@ -537,7 +537,7 @@ public string ClampString(string str, int? min = null, int? max = null)
       /// </summary>
       /// <typeparam name="T">Must be an Enum</typeparam>
       /// <param name="exclude">Exclude enum values from being returned</param>
-      public T Enum<T>(params T[] exclude) where T : struct
+      public T Enum<T>(params T[] exclude) where T : struct, Enum
       {
          var e = typeof(T);
          if( !e.IsEnum() )
@@ -558,8 +558,7 @@ public string ClampString(string str, int? min = null, int? max = null)
 
          var val = this.ArrayElement(selection);
 
-         T picked;
-         System.Enum.TryParse(val, out picked);
+         System.Enum.TryParse(val, out T picked);
          return picked;
       }