Extracted the logic for getting wrapped units.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/AST/ClassExtensions.cs

@@ -198,5 +198,11 @@ namespace CppSharp.AST
 
             return hasRefBase;
         }
+
+        public static IEnumerable<TranslationUnit> GetGenerated(this IEnumerable<TranslationUnit> units)
+        {
+            return units.Where(u => u.IsValid && !u.IsSystemHeader &&
+                u.IsGenerated && u.HasDeclarations);
+        }
     }
 }

src/Generator/Driver.cs

@@ -527,7 +527,7 @@ namespace CppSharp
             }
 
             new CleanUnitPass(options).VisitLibrary(driver.ASTContext);
-            options.Modules.RemoveAll(m => m.Units.All(u => u.Declarations.Count == 0));
+            options.Modules.RemoveAll(m => !m.Units.GetGenerated().Any());
 
             if (!options.Quiet)
                 Log.Message("Processing code...");

src/Generator/Generator.cs

@@ -71,8 +71,7 @@ namespace CppSharp.Generators
         {
             var outputs = new List<GeneratorOutput>();
 
-            var units = Driver.ASTContext.TranslationUnits.Where(
-                u => u.IsGenerated && u.HasDeclarations && !u.IsSystemHeader && u.IsValid).ToList();
+            var units = Driver.ASTContext.TranslationUnits.GetGenerated().ToList();
             if (Driver.Options.IsCSharpGenerator)
                 GenerateSingleTemplate(outputs);
             else
@@ -118,8 +117,7 @@ namespace CppSharp.Generators
                         FilePath = string.Format("{0}.cs", module.LibraryName),
                         Module = module
                     },
-                    Templates = Generate(module.Units.Where(
-                        u => u.IsGenerated && u.HasDeclarations && !u.IsSystemHeader && u.IsValid))
+                    Templates = Generate(module.Units.GetGenerated())
                 };
                 output.Templates[0].Process();
                 outputs.Add(output);

src/Generator/Passes/DelegatesPass.cs

@@ -40,8 +40,7 @@ namespace CppSharp.Passes
             foreach (var library in Driver.Options.Modules.SelectMany(m => m.Libraries))
                 libsDelegates[library] = new Dictionary<string, DelegateDefinition>();
 
-            var unit = context.TranslationUnits.LastOrDefault(u => u.IsValid && u.IsGenerated &&
-                u.HasDeclarations);
+            var unit = context.TranslationUnits.GetGenerated().LastOrDefault();
 
             if (unit == null)
                 return false;