Created attachment 95377 [details]
Simple source file that will show two validation errors in NetBeans

Example from attachment:

namespace test {
class TestClass {
public:
    TestClass();
    TestClass(const TestClass& orig);
    virtual ~TestClass();
private:
    class Private;
    Private *d;
};
}

using namespace test;

class TestClass::Private { // NetBeans won't find the Private identifier
public:
    int unresolved_identifier;
};

TestClass::TestClass() { d = new Private; }
TestClass::TestClass(const TestClass& orig) { d = new Private; }
TestClass::~TestClass() {
    int this_will_be_flagged_as_wrong = d->unresolved_identifier;
    delete d;
}

Here is inner class definition in different namespace with parent class.

It's rare scenario and it's very time expensive to search definition for declaration in whole project.