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c++stringc++17string-view

Can I use std::string_view with getline when parsing a file?

I recently learned about std::string_view and how it is much faster than allocating strings so I am trying to use this in place of std::string where possible.

Is there a way of optimizing a loop that parses a file line by line to use std::string_view instead?

This is the code I am working on.

    std::string line;

    // loop until we find the cabbage tag
    while (std::getline(csd, line))
    {
        //DO STUFF
        if (line.find("</STOP>") != std::string::npos)
            break;
    }
Solution

  • What you're looking for is mmap, that allows you to read into a file's data without copying them. Reading from a stream in C++ will always copy the data. You can then, of course, use std::string_view to point at the data revealed by mmap, and do all operations you like.