Split string according to character-combination/ at `\n` - c++

Question

What is the right way to split a string like below at a specific character-combination into a string vector?
string myString = "This is \n a test. Let's go on. \n Yeah.";
split at "\n" to get this result:
vector<string> myVector = {
"This is ",
" a test. Let's go on. ",
" Yeah."
}
I was using boost algorithm library but now I'd like to achieve this all without using an external library like boost.
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/split.hpp>
std::vector<std::string> result;
boost::split(result, "This is \n a test. Let's go on. \n Yeah.",
boost::is_any_of("\n"), boost::token_compress_on);

Answer 1

How about something like this:
#include <iostream>
#include <sstream>
#include <vector>
#include <string>
#include <iterator>
class line : public std::string {};
std::istream &operator>>(std::istream &iss, line &line)
{
std::getline(iss, line, '\n');
return iss;
}
int main()
{
std::istringstream iss("This is \n a test. Let's go on. \n Yeah.");
std::vector<std::string> v(std::istream_iterator<line>{iss}, std::istream_iterator<line>{});
// test
for (auto const &s : v)
std::cout << s << std::endl;
return 0;
}
Basically make a new type of string which is line and use stream iterator to read whole lines straight to vector range constructor
Working demo: https://ideone.com/4qdfY2

Answer 2

Solution 1: Just to remove "\n" from the string.
Just to remove "\n", you can use erase-remove idiom . SEE LIVE HERE
#include <iostream>
#include <string>
#include <algorithm>
int main()
{
std::string myString = "This is \n a test. Let's go on. \n Yeah.";
myString.erase(std::remove(myString.begin(), myString.end(), '\n'),
myString.end());
std::cout << myString<< std::endl;
}
Output:
This is a test. Let's go on. Yeah
Solution 2: To remove "\n" from the string and save each split at \n to a vector. (un-efficient)
Replace all \n occurance with some other charectors, which doesn't exist in the string (here I have chosen ;). Then parse with the help of std::stringstream and std::getline as follows. SEE LIVE HERE
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <sstream>
int main()
{
std::string myString = "This is \n a test. Let's go on. \n Yeah.";
std::replace(myString.begin(), myString.end(), '\n', ';');
std::stringstream ssMyString(myString);
std::string each_split;
std::vector<std::string> vec;
while(std::getline(ssMyString, each_split, ';')) vec.emplace_back(each_split);
for(const auto& it: vec) std::cout << it << "\n";
}
Output:
This is
a test. Let's go on.
Yeah.
Solution 3: To remove "\n" from the string and save each split at \n to a vector.
Loop through the string and find positions(using std::string::find) where \n(end position) finds. Push back the substrings (std::string::substr) using the information of starting position and the number of charectors between start and end position. Each time update the start and end positions, so that look up will not start again from the beging of the input string. SEE LIVE HERE
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstddef>
int main()
{
std::string myString = "This is \n a test. Let's go on. \n Yeah.";
std::vector<std::string> vec;
std::size_t start_pos = 0;
std::size_t end_pos = 0;
while ((end_pos = myString.find("\n", end_pos)) != std::string::npos)
{
vec.emplace_back(myString.substr(start_pos, end_pos - start_pos));
start_pos = end_pos + 1;
end_pos += 2;
}
vec.emplace_back(myString.substr(start_pos, myString.size() - start_pos)); // last substring
for(const auto& it: vec) std::cout << it << "\n";
}
Output:
This is
a test. Let's go on.
Yeah.