How to use coro_file

[qicosmos]

sequence read and write file.

create and write file

    std::string filename = "app_file.txt";
    coro_io::coro_file file{};
    file.open(filename, std::ios::out);
    CHECK(file.is_open());
    async_simple::coro::syncAwait(file.async_write("it is a test"));
    file.close();

append file

    std::string filename = "app_file.txt";
    coro_io::coro_file file{};
    file.open(filename, std::ios::app);
    CHECK(file.is_open());
    async_simple::coro::syncAwait(file.async_write("it is a test"));
    file.close();

read file

    std::string filename = "app_file";
    coro_io::coro_file file{};
    file.open(filename, std::ios::in);
    CHECK(file.is_open());
    std::string buf;
    buf.resize(40);
    auto [ec, sz] = async_simple::coro::syncAwait(file.async_read(buf.data(), buf.size()));
    std::cout << std::string_view(buf.data(), sz) << "\n"; //output: it is a testit is a test

http server

  coro_http_server server(1, 9001);
  server.set_http_handler<GET>(
      "/get", [](coro_http_request &req, coro_http_response &resp) {
        resp.set_status_and_content(status_type::ok, "ok");
      });

  server.set_http_handler<GET>(
      "/coro",
      [](coro_http_request &req,
         coro_http_response &resp) -> async_simple::coro::Lazy<void> {
        std::string filename = "test.log";
        coro_io::coro_file file{};
        file.open(filename, std::ios::app);
        if (file.is_open()) {
          std::string content = "test";
          co_await file.async_write(content);
          file.close();
        }
        resp.set_status_and_content(status_type::ok, "ok");
        co_return;
      });
  server.async_start();

//test code
coro_http_client client{};
auto result = co_await client.async_get("http://127.0.0.1:9001/coro");
assert(result.status == 200);