文件名創建Ifstream對象時出錯

Question

失敗的任何特定原因？

    std::string r = "Hej.whatever";
    std::string const *p = &r;
    std::ifstream file ((*p).c_str(), std::ios::in, std::ios::ate);
    std::ifstream file ((*p), std::ios::in, std::ios::ate);

error: no matching function for call to
  ‘std::basic_ifstream<char>::basic_ifstream(const string&,
               const openmode&, const openmode&)’
  std::ifstream file ((*p), std::ios::in, std::ios::ate);

Answer 1

您需要按位OR（ | ）傳遞幾種模式：

std::ifstream file ((*p), std::ios::in | std::ios::ate);
std::ifstream file2 ((*p), std::ios::in | std::ios::ate);

您可以從第一次調用中刪除.c_str() ，而無需使用它