C++写入并追加内容到txt中

C++写入并追加内容到txt中，即已有一个txt文件，里面有数据，需要将现在数据继续放在已有数据后面

	fstream f;
	f.open("convex.txt", ios::out | ios::app);
	f << "h = " << slice_height << "," << "A = " << each_strip_angle << endl;
	for (int i = 0; i < Defection_quantification_concave.size(); i++)
	{
		f << Defection_quantification_concave.at(i).defection_area;
		f << ",";
		f << Defection_quantification_concave.at(i).defection_volume;
		f << endl;
	}
	f.close();

参考：https://blog.csdn.net/m0_37576376/article/details/122930015