c++ - std::getline skipping input from std::cin after last occurrence of delimiter, but not with input from std::istringstream -

i need read input delimited whitespace, main construction used is:

while(std::getline(std::cin, s, ' ')){     std::cout << s << std::endl; } 

for input: "this text"

output s be: "this", "is", "some", skipping last piece of input after last whitespace.

want include last piece of input in program well, went looking solution , found following:

while (std::getline(std::cin, line)) {     std::istringstream iss(line);      while (std::getline(iss, s, ' ')) {         std::cout << s << std::endl;     } } 

for input: "this text"

the output s be: "this", "is", "some", "text", want.

my question is: why reading std::cin delimiter skip input after last occurrence of delimiter, reading std::istringstream not?

my question is: why reading std::cin delimiter skip input after last occurrence of delimiter, reading std::istringstream not?

it doesn't.

in first example:

while(std::getline(std::cin, s, ' ')){     std::cout << s << std::endl; } 

you reading items newline literally delimited single space. because line (ostensibly) ended newline, never finish extracting input string expecting either ' ' or eof.

in second example:

while (std::getline(std::cin, line)) {     std::istringstream iss(line);      while (std::getline(iss, s, ' ')) {         std::cout << s << std::endl;     } } 

the std::getline in first while strip newline example sentence. items extracted according basic rules.

here rules (from cppreference):

extracts characters input , appends them str until 1 of following occurs (checked in order listed)     a) end-of-file condition on input, in case, getline sets eofbit.     b) next available input character delim, tested traits::eq(c, delim), in case delimiter character extracted input, not appended str.     c) str.max_size() characters have been stored, in case getline sets failbit , returns.