Unresolved C++11 symbols in DS-5

I'm developing ARM Linux C++11 project on Windows DS-5 with arm-linux-gnueabihf-g++.

My issue is that C++11 symbols are underlined as not-resolved and code completion for these symbols does not work.

The project builds and runs OK.

I created a new "Hello World C++ Project" with GCC compiler.
I enabled C++11 in Project > Properties > C/C++ Build > Settings > Tool Settings > GCC C++ Compiler > Dialect = ISO C++11.

My main.c:

#include <iostream>
#include <memory>

using namespace std;

int main() {
	cout << "Hello World!!!" << endl;

	unique_ptr<int> pi;

	return 0;
}

Only unique_ptr symbol is unresolved in the editor. The only way to make it resolved is to include full path to its header:
#include "c:\\intelFPGA\\18.1\\embedded\\ds-5\\sw\\gcc\\arm-linux-gnueabihf\\include\\c++\\4.8.3\\bits\\unique_ptr.h" But this is of course is not a proper solution.

Adding the above path to Include Paths in compiler settings does not help.