ios::trunc 如何在 C++ 中为二进制文件工作？

Question

When I write fout.open("file.dat",ios::out|ios::trunc|ios::binary); does the file loose all its data at that instance or it will wait for something to be written and then data will be lost? (I hope you get my point, all I'm asking is whether just writting the above statement, ie fout.write() will invoke removal of records from a binary file or we need to pass some data to the file and then the previous data already stored in the file would be lost)

Answer 1

trunc 标志将在 open() 处将文件清零。