stringstream basically allows you to treat a string object like a stream, and use all stream functions and operators on it. I saw it used mainly for the formatted output/input goodness. One good example would be c++ implementation of converting number to stream object.

2014年2月21日 · At this point, the compiler is oblivious to the stringstream to which the result of the expression will be passed. A solution for stringstream. It's a bit of a chicken-and-egg problem, because you need to combine the right-hand values you want in the stringstream to call the stringstream's constructor, but for that you need... a stringstream.

2008年11月23日 · In C and/or Unix, the basic metaphor was the file. Standard out, standard in, network sockets were all represented using file descriptors.

2015年5月6日 · const std::string tmp = stringstream.str(); const char* cstr = tmp.c_str(); Note that I made the temporary string const, because any changes to it might cause it to re-allocate and thus render cstr invalid. It is therefor safer to not to store the result of the call to str() at all and use cstr only until the end of the full expression:

A stringstream is somewhat larger, and might have slightly lower performance -- multiple inheritance can require an adjustment to the vtable pointer. The main difference is (at least in theory) better expressing your intent, and preventing you from accidentally using >> where you intended << (or vice versa).

2009年3月19日 · Use the .str()-method:. Manages the contents of the underlying string object. 1) Returns a copy of the underlying string as if by calling rdbuf()->str().

2013年2月7日 · In a recent set of benchmarks conducted on Quick-Bench, std::stringstream demonstrated lower performance compared to concatenating strings using the std::string += operator. This is a notable finding because appending multiple strings and literals is a frequent operation in string processing.

2013年1月2日 · calling reserve on an empty string yields an empty string, so stringstream constructor doesn't need to allocate to copy the contents of that string. seekp on a stringstream still seems to be undefined behavior and/or does nothing. The Good. This code segment works as expected, with ss being preallocated with the requested size.

2011年4月29日 · A fairer comparison would be comparing stringstream to the sprintf/sscanf line of functions, which would be slower than strtod() but still faster than stringstream. I'm not exactly sure what makes stringstream's design slower than …

Either you don't have a using namespace std in your code or you're not fully qualifying calls made to the API's in the std namespace with an std:: prefix, for example, std::getline().