How do I stream large files efficiently in C++?

Streaming large files efficiently in C++ requires using buffered I/O and proper management of system resources. Here’s a guide and example to help you understand how to do it effectively.

#include <iostream>
#include <fstream>
#include <vector>

void streamLargeFile(const std::string &filename) {
    std::ifstream inputFile(filename, std::ios::binary);
    if (!inputFile) {
        std::cerr << "Error opening file!" << std::endl;
        return;
    }
    
    // Buffer to read chunks of data
    std::vector buffer(1024 * 1024); // 1 MB buffer
    while (inputFile.read(buffer.data(), buffer.size()) || inputFile.gcount() > 0) {
        // Process the data in buffer
        std::cout.write(buffer.data(), inputFile.gcount());
    }
    
    inputFile.close();
}

int main() {
    streamLargeFile("large_file.dat");
    return 0;
}