File-Reader Function doesn't work with VST3 SDK?

Hi,
I’m doing a plugin that needs to charge a .obj or another 3d object file and this is the function with which I can read files but I don’t know why “ifstream” doesn’t work. I’m working with OpenGL.

// Reads a text file and outputs a string with everything in the text file
std::string get_file_contents(const char* filename)
{
	
	std::ifstream in(filename, std::ios::binary);
	
	if (in)
	{
		std::string contents;
		in.seekg(0, std::ios::end);
		contents.resize(in.tellg());
		in.seekg(0, std::ios::beg);
		in.read(&contents[0], contents.size());
		in.close();
		return(contents);
	}

	throw(errno);
}

Did you check the example implementation in the VST 3 SDK?
public.sdk/source/common/readfile.h