Generate valid C# for implicit conversion to const char*

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

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -2901,7 +2901,6 @@ namespace CppSharp.Generators.CSharp
                     ArgName = Helpers.ReturnIdentifier,
                     ReturnVarName = Helpers.ReturnIdentifier,
                     ReturnType = returnType,
-                    Parameter = operatorParam,
                     Function = function
                 };
 

tests/CSharp/CSharp.Tests.cs

@@ -1276,7 +1276,17 @@ public unsafe class CSharpTests : GeneratorTestFixture
     }
 
     [Test]
-    public void Test()
+    public void TestImplicitConversionToString()
+    {
+        using (Foo foo = new Foo())
+        {
+            string name = foo;
+            Assert.That(name, Is.EqualTo("test"));
+        }
+    }
+
+    [Test]
+    public void TestHasFunctionPointerField()
     {
         using (var hasFunctionPtrField = new HasFunctionPtrField())
         {

tests/CSharp/CSharp.cpp

@@ -104,6 +104,11 @@ int Foo::operator --()
     return 4;
 }
 
+Foo::operator const char*() const
+{
+    return "test";
+}
+
 const Foo& Bar::operator[](int i) const
 {
     return m_foo;

tests/CSharp/CSharp.h

@@ -38,6 +38,7 @@ public:
 
     int operator ++();
     int operator --();
+    operator const char*() const;
 
     bool btest[5];
     QFlags<TestFlag> publicFieldMappedToEnum;