Function CountCharFileCoroImpl

demo_example/ReadFiles.cpp:125–132

The *Impl is not the key point for this example, code readers could ignore this.

// The *Impl is not the key point for this example, code readers
// could ignore this.
Lazy<uint64_t> CountCharFileCoroImpl(const FileName &File, char c) {
    uint64_t Ret = 0;
    std::ifstream infile(File);
    std::string line;
    while (std::getline(infile, line))
        Ret += std::count(line.begin(), line.end(), c);
    co_return Ret;
}

Lazy<uint64_t> CountCharInFilesCoro(const std::vector<FileName> &Files,
                                    char c) {