How I can get map<sting, int> from C++ to C#

extern "C" __declspec(dllexport) map<string, int> createMap(string &fileName) {
	ifstream infile(fileName);
	vector<string> bitsLine;
	bool headerEnded = false;
	string line;
	int i = 0;
	int length = 0;

	while (getline(infile, line)) {
		if (headerEnded) {
			bitsLine = split(line, ',');
			signalsMap.insert({ bitsLine.at(0), length });
		}
		else {
			if (line.find("HEADER_END") != std::string::npos) {
				headerEnded = true;
			}
		}
		length = infile.tellg();
		i++;
	}
	return signalsMap;
}

Dictionary<string, int>  x =  createMap("C:/users/asalah/source/repos/WindowsFormsApp3/WindowsFormsApp3/RR_Test2_3.csv");