Writing from one large file to other with fstream::rdbuf

std::ifstream inFile;
std::ofstream outFile;
// open files
outFile << inFile.rdbuf();

I so far can't find info about how rdbuf() works. My concern is big files - if inFile is larger than operating memory will the following code crash with overflow, or rdbuf() will be able to redirect one file to another of any size?