Not able to use Directory::getFiles() directly in the code

I am trying to get few files from a path of specific pattern and for this I am using the command below which is giving me an error:

std::vector<std::string> cppFiles;
cppFiles = System::IO::Directory::GetFiles(path, "*.cpp" );

Error is on "System" and it says:- name followed by :: must be a class or namespace name.

I even tried putting using namespace System, still I am getting the same error on namespace as well.

Am开发者_JAVA技巧 I missing something?

You are obviously not including the relevant header.