Fixed the generated C# when an operator returns a template.

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

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -2301,7 +2301,7 @@ namespace CppSharp.Generators.CSharp
                 }
                 else if (method.IsOperator)
                 {
-                    GenerateOperator(method);
+                    GenerateOperator(method, returnType);
                 }
                 else if (method.SynthKind == FunctionSynthKind.AbstractImplCall)
                 {
@@ -2324,7 +2324,7 @@ namespace CppSharp.Generators.CSharp
                 }
                 else if (method.IsOperator)
                 {
-                    GenerateOperator(method);
+                    GenerateOperator(method, returnType);
                 }
                 else
                 {
@@ -2482,7 +2482,7 @@ namespace CppSharp.Generators.CSharp
             return delegateId;
         }
 
-        private void GenerateOperator(Method method)
+        private void GenerateOperator(Method method, QualifiedType returnType)
         {
             if (method.SynthKind == FunctionSynthKind.ComplementOperator)
             {
@@ -2533,7 +2533,7 @@ namespace CppSharp.Generators.CSharp
                     method.OperatorKind == CXXOperatorKind.EqualEqual ? string.Empty : ")");
             }
 
-            GenerateInternalFunctionCall(method);
+            GenerateInternalFunctionCall(method, returnType: returnType);
         }
 
         private void GenerateClassConstructor(Method method, Class @class)

tests/CSharp/CSharp.Tests.cs

@@ -799,6 +799,20 @@ public unsafe class CSharpTests : GeneratorTestFixture
         }
     }
 
+    [Test]
+    public void TestOperatorReturnTemplateValue()
+    {
+        using (var dependentValueFields = new DependentValueFields<int>())
+        {
+            using (var other = new DependentValueFields<int>())
+            {
+                dependentValueFields.DependentValue = 10;
+                other.DependentValue = 15;
+                Assert.That((dependentValueFields + other).DependentValue, Is.EqualTo(25));
+            }
+        }
+    }
+
     [Test]
     public void TestAbstractImplementatonsInPrimaryAndSecondaryBases()
     {

tests/CSharp/CSharpTemplates.h

@@ -115,6 +115,7 @@ public:
     ~DependentValueFields();
     DependentValueFields& returnInjectedClass();
     DependentValueFields returnValue();
+    DependentValueFields operator+(const DependentValueFields& other);
     T getDependentValue();
     void setDependentValue(const T& value);
 private:
@@ -158,6 +159,14 @@ DependentValueFields<T> DependentValueFields<T>::returnValue()
     return *this;
 }
 
+template <typename T>
+DependentValueFields<T> DependentValueFields<T>::operator+(const DependentValueFields& other)
+{
+    DependentValueFields<T> sum;
+    sum.field = field + other.field;
+    return sum;
+}
+
 template <typename T>
 class DLL_API DependentPointerFields
 {