p-ranav/csv2

#include <csv2/reader.hpp>

int main() {
  csv2::Reader<csv2::delimiter<','>, 
               csv2::quote_character<'"'>, 
               csv2::first_row_is_header<true>,
               csv2::trim_policy::trim_whitespace> csv;
               
  if (csv.mmap("foo.csv")) {
    const auto header = csv.header();
    for (const auto row: csv) {
      for (const auto cell: row) {
        // Do something with cell value
        // std::string value;
        // cell.read_value(value);
      }
    }
  }
}

template <class delimiter = delimiter<','>, 
          class quote_character = quote_character<'"'>,
          class first_row_is_header = first_row_is_header<true>,
          class trim_policy = trim_policy::trim_whitespace>
class Reader {
public:
  
  // Use this if you'd like to mmap and read from file
  bool mmap(string_type filename);

  // Use this if you have the CSV contents in std::string already
  bool parse(string_type contents);

  // Shape
  size_t rows() const;
  size_t cols() const;
  
  // Row iterator
  // If first_row_is_header, row iteration will start
  // from the second row
  RowIterator begin() const;
  RowIterator end() const;

  // Access the first row of the CSV
  Row header() const;
};

// Row class
class Row {
public:
  // Get raw contents of the row
  void read_raw_value(Container& value) const;
  
  // Cell iterator
  CellIterator begin() const;
  CellIterator end() const;
};

// Cell class
class Cell {
public:
  // Get raw contents of the cell
  void read_raw_value(Container& value) const;
  
  // Get converted contents of the cell
  // Handles escaped content, e.g., 
  // """foo""" => ""foo""
  void read_value(Container& value) const;
};

#include <csv2/writer.hpp>
#include <vector>
#include <string>
using namespace csv2;

int main() {
    std::ofstream stream("foo.csv");
    Writer<delimiter<','>> writer(stream);

    std::vector<std::vector<std::string>> rows = 
        {
            {"a", "b", "c"},
            {"1", "2", "3"},
            {"4", "5", "6"}
        };

    writer.write_rows(rows);
    stream.close();
}

template <class delimiter = delimiter<','>>
class Writer {
public:
  
  // Construct using an std::ofstream
  Writer(output_file_stream stream);

  // Use this to write a single row to file
  void write_row(container_of_strings row);

  // Use this to write a list of rows to file
  void write_rows(container_of_rows rows);