Sample code for a hypothetical Objective-C++/CLI language.

objcppcli.mm

#include <iostream>
#include <msclr/marshal.h>
#include <msclr/marshal_cppstd.h>
#import <Foundation/Foundation.h>

// Sample code for a hypothetical Objective-C++/CLI language

ref class ClrClass;
@class ObjCClass;

class CppClass {
	void hello_from(std::string sender);
	void greet(ObjCClass *target);
	void greet(ClrClass ^target);
};

ref class ClrClass {
	void HelloFrom(System::String ^sender);
	void Greet(CppClass &target);
	void Greet(ObjCClass *target);
};

@interface ObjCClass : NSObject
- (void)helloFrom:(NSString *)sender;
- (void)greetCPP:(CppClass &)target;
- (void)greetCLR:(ClrClass ^)target;
@end

// C++ class implementation

void CppClass::hello_from(std::string sender)
{
	std::cout << "C++ greeted by " << sender << std::endl;
}

void CppClass::greet(ObjCClass *target)
{
	std::string sender = "C++";
	NSString *nsstr = [NSString stringWithUTF8String:sender.c_str()];
	[target helloFrom:nsstr];
}

void CppClass::greet(ClrClass ^target)
{
	std::string sender = "C++";
	System::String ^clrstr = marshal_as<System::String^>(sender);
	target.HelloFrom(clrstr);
}

// C++/CLI class implementation

void ClrClass::HelloFrom(System::String ^sender)
{
	System::Console::WriteLine("C++/CLI greeted by {0}", sender);
}

void ClrClass::Greet(CppClass &target)
{
	System::String ^sender = "C++/CLI";
	std::string stdstr = marshal_as<std::string>(sender);
	target.hello_from(stdstr);
}

void ClrClass::Greet(ObjCClass *target)
{
	System::String ^sender = "C++/CLI";
	std::string stdstr = marshal_as<std::string>(sender);
	NSString *nsstr = [NSString stringWithUTF8String:stdstr.c_str()];
	[target helloFrom:nsstr];
}

// Objective-C class implementation

@implementation ObjCClass 

- (void)helloFrom:(NSString *)sender
{
	NSLog(@"Objective-C greeted by %@", sender);
}

- (void)greetCPP:(CppClass &)target
{
	NSString *sender = @"Objective-C";
	std::string stdstr = [sender UTF8String];
	target.hello_from(stdstr);
}

- (void)greetCLR:(ClrClass ^)target
{
	NSString *sender = @"Objective-C";
	System::String ^clrstr = marshal_as<std::string>(sender);
	target.HelloFrom(clrstr);
}

@end

int main(int argc, const char *argv[])
{
	CppClass cpp;
	ClrClass ^clr = gcnew ClrClass();
	ObjCClass *objc = [ObjCClass new];

	cpp.greet(clr);
	cpp.greet(objc);
	clr.Greet(cpp);
	clr.Greet(objc);
	[objc greetCPP:cpp];
	[objc greetCLR:clr];

	return 0;
}

This would be insane. How come it doesn't exist? Such pity xxD.