• Alain De Vos (25/25) Apr 28 2021 Is it ok to do the following ?
• Alain De Vos (8/8) Apr 28 2021 PS: I managed to link to phobo's/runtime & wxgtk at the same time.
• Alain De Vos (20/20) Apr 28 2021 Following code produces a linker error.
• Adam D. Ruppe (5/15) Apr 28 2021 idk what you intend to do with this, this pattern is for merging
• evilrat (2/4) Apr 28 2021 It's virtual by default. The opposite is `final`.
• user1234 (2/8) Apr 29 2021 by default, excepted if protection is private or package.

Alain De Vos <devosalain ymail.com> writes:

Is it ok to do the following ?
I.e. derive  a D-class from a CPP-class.
The compiler did not complained, and it was OK for him.
```
c++ -c MyClass.cpp
ldc2 main.d MyClass.o -L-lstdc++
```

```
extern(C++){
	class MyClass {
		public:
			int num=1;
			void myMethod();
	};
};

class Derived : MyClass{
};

int main(){
	Derived myObj;
	myObj.myMethod();
	return 0;
}

```

Could I use this method for using the C++-WXWIDGETS library 
directly?

Alain De Vos <devosalain ymail.com> writes:

PS: I managed to link to phobo's/runtime & wxgtk at the same time.
It goes like this [So someone does not need to re-invent the weel]

```
ldc2 - c test.d
c++ test.o -o test -L/usr/local/lib -lphobos2-ldc -ldruntime-ldc 
-Wl,--gc-sections -lexecinfo -lpthread -lm -m64 
`wxgtk3u-3.0-config --cxxflags --libs`

```

Alain De Vos <devosalain ymail.com> writes:

Following code produces a linker error.
d: error: undefined symbol: wxApp::OnInit()
```
extern(C++)
	{class wxApp {
			public:
			bool OnInit();
			//virtual bool Oninit();
		}
	}

class MYAPP: wxApp {
			alias OnInit=wxApp.OnInit;
			bool OnInit(){return true;};
}

int main(){
	return 0;
}
```
It is rather clear what I want to achieve but virtual functions 
give me headache because dlang does not now the word virtual.

Adam D. Ruppe <destructionator gmail.com> writes:

On Wednesday, 28 April 2021 at 19:46:00 UTC, Alain De Vos wrote:
 Following code produces a linker error.
 d: error: undefined symbol: wxApp::OnInit()
 ```
 extern(C++)
 	{class wxApp {
 			public:
 			bool OnInit();
 			//virtual bool Oninit();

you mean `abstract` for that one?


 			alias OnInit=wxApp.OnInit;

idk what you intend to do with this, this pattern is for merging 
overloads not overriding

 			bool OnInit(){return true;};

and you might want `override` there

evilrat <evilrat666 gmail.com> writes:

On Wednesday, 28 April 2021 at 19:46:00 UTC, Alain De Vos wrote:
 It is rather clear what I want to achieve but virtual functions 
 give me headache because dlang does not now the word virtual.

It's virtual by default. The opposite is `final`.

user1234 <user1234 12.de> writes:

On Thursday, 29 April 2021 at 06:38:53 UTC, evilrat wrote:
 On Wednesday, 28 April 2021 at 19:46:00 UTC, Alain De Vos wrote:
 It is rather clear what I want to achieve but virtual 
 functions give me headache because dlang does not now the word 
 virtual.

 It's virtual by default. The opposite is `final`.

by default, excepted if protection is private or package.