我正在使用一个istringstream
逐字读取string
。但是,当我的条件失败时,我需要能够将istringstream
恢复到上一个单词被读取之前。我的示例代码有效,但我想知道是否有更直接的方式来使用流来完成此操作。如何保存和恢复std :: istringstream的缓冲区?
std::string str("my string");
std::istringstream iss(str);
std::ostringstream ossBackup << iss.rdbuf(); // Writes contents of buffer and in the process changes the buffer
std::string strBackup(ossBackup.str()); // Buffer has been saved as string
iss.str(strBackup); // Use string to restore iss's buffer
iss.clear(); // Clear error states
iss >> word; // Now that I have a backup read the 1st word ("my" was read)
// Revert the `istringstream` to before the previous word was read.
iss.str(strBackup); // Restore iss to before last word was read
iss.clear(); // Clear error states
iss >> word; // "my" was read again
那么,这似乎取决于你如何定义_“当我的情况失败”_完全。你可以检查'operator >>()'操作留下的值,并且设置流状态失败。这是一个[示例](http://stackoverflow.com/questions/24504582/test-whether-stringstream-operator-has-parsed-a-bad-type?noredirect=1#comment37965807_24504582)。 – 2014-10-06 18:28:58