c++ split string by double newline -

i have been trying split string double newlines ("\n\n").

input_string = "firstline\nsecondline\n\nthirdline\nfourthline"; size_t current; size_t next = std::string::npos; { current = next + 1; next = input_string.find_first_of("\n\n", current); cout << "[" << input_string.substr(current, next - current) << "]" << endl; } while (next != std::string::npos); 

gives me output

[firstline] [secondline] [] [thirdline] [fourthline] 

which not wanted. need like

[first line second line] [third line fourthline] 

i have tried boost::split gives me same result. missing?

find_first_of looks single characters. you're telling passing "\n\n", find first of either '\n' or '\n', , that's redundant. use string::find instead.

boost::split works examining 1 character @ time.