Ways std::stringstream can set fail/bad bit?
- by Evan Teran
A common piece of code I use for simple string splitting looks like this:
inline std::vector<std::string> split(const std::string &s, char delim) {
std::vector<std::string> elems;
std::stringstream ss(s);
std::string item;
while(std::getline(ss, item, delim)) {
elems.push_back(item);
}
return elems;
}
Someone mentioned that this will silently "swallow" errors occurring in std::getline. And of course I agree that's the case. But it occurred to me, what could possibly go wrong here in practice that I would need to worry about. basically it all boils down to this:
inline std::vector<std::string> split(const std::string &s, char delim) {
std::vector<std::string> elems;
std::stringstream ss(s);
std::string item;
while(std::getline(ss, item, delim)) {
elems.push_back(item);
}
if(ss.fail()) {
// *** How did we get here!? ***
}
return elems;
}
A stringstream is backed by a string, so we don't have to worry about any of the issues associated with reading from a file. There is no type conversion going on here since getline simply reads until it sees a newline or EOF. So we can't get any of the errors that something like boost::lexical_cast has to worry about.
I simply can't think of something besides failing to allocate enough memory that could go wrong, but that'll just throw a std::bad_alloc well before the std::getline even takes place. What am I missing?
