class Blah{
    int x {0};

  public:
    Blah() = default;
    int get(){ return this->x; }
};

int main(){
  Blah a;
  a.get();
  return 0;
}

#include "test.hpp"

int main(){
  Blah a;
  a.get();
  a.getVal();
  return 0;
}

#ifndef TEST_HPP_
#define TEST_HPP_

class Blah{
    int x {0};

  public:
    Blah() = default;
    int getVal(){ return this->x;}
};

#endif /* TEST_HPP_ */

#ifndef OBJECT_HPP_
#define OBJECT_HPP_

namespace stuff {
  class Object{
    friend class Builder; // Only connector can instantiate a Builder object.

    explicit
    Object()
    {};

    public:
      virtual
      ~Object() = default;
  };
}

#endif /* OBJECT_HPP_ */

#ifndef CONNECTOR_HPP_
#define CONNECTOR_HPP_

#include <memory>
#include "object.hpp"

namespace stuff {
  class Builder{
    public:
      enum class OPTIONS : uint32_t{
        OPTION_1 = 1,
      };

    private:
      std::shared_ptr<OPTIONS> opts {nullptr};

    public:
      Builder() = default;

      virtual
      ~Builder() = default;

      explicit
      Builder(const Builder::OPTIONS& ops)
      : opts {std::make_shared<OPTIONS>(ops)}
      {}
  };
}

#endif /* CONNECTOR_HPP_ */

#include <iostream>
#include "builder.hpp"
#include "object.hpp"

using namespace std;
using namespace stuff;

int main() {
  Builder c(Builder::OPTIONS::OPTION_1);

  return 0;
}

Builder c(Builder::OPTIONS::OPTION_1);

#ifndef FOO_H_
#define FOO_H_

#include <memory>

class Foo {
public:
	std::shared_ptr<int> m_variable = nullptr;
};

#endif /* FOO_H_ */

#include <memory>
#include "foo.h"

int main() {
	Foo a;

	std::exit(0);
}

Project:               eclipse_error
File:                  file:/home/jonas/eclipse_workspaces/c++/eclipse_error/main.cpp
Language:              GNU C++
Index Version:         206.0
Build Configuration:   Debug
Context:               file:/home/jonas/eclipse_workspaces/c++/eclipse_error/main.cpp
   C++, {}
Versions in Index:     1
   C++: {}; 0 macros, 2 includes, 5 names;

Include Search Path (option -I):
   /home/jonas/eclipse_workspaces/c++/eclipse_error
   /usr/include/c++/6.2.1
   /usr/include/c++/6.2.1/x86_64-pc-linux-gnu
   /usr/include/c++/6.2.1/backward
   /usr/lib/gcc/x86_64-pc-linux-gnu/6.2.1/include
   /usr/local/include
   /usr/lib/gcc/x86_64-pc-linux-gnu/6.2.1/include-fixed
   /usr/include

...

Unresolved includes (from headers in index):
   file:/home/jonas/eclipse_workspaces/c++/eclipse_error/foo.h is not indexed

Unresolved names:
   Attempt to use symbol failed: Foo in file /home/jonas/eclipse_workspaces/c++/eclipse_error/main.cpp:5

Written on Mon Jan 02 18:49:46 CET 2017