changing the delimiter for cin (c++)

Question

I've redirected "cin" to read from a file stream cin.rdbug(inF.rdbug()) When I use the extraction operator it reads until it reaches a white space character.

Is it possible to use another delimiter? I went through the api in cplusplus.com, but didn't find anything.

Answer 1

It is possible to change the inter-word delimiter for cin or any other std::istream, using std::ios_base::imbue to add a custom ctype facet.

If you are reading a file in the style of /etc/passwd, the following program will read each :-delimited word separately.

#include <locale> #include <iostream>   struct colon_is_space : std::ctype<char> {   colon_is_space() : std::ctype<char>(get_table()) {}   static mask const* get_table()   {     static mask rc[table_size];     rc[':'] = std::ctype_base::space;     rc['\n'] = std::ctype_base::space;     return &rc[0];   } };  int main() {   using std::string;   using std::cin;   using std::locale;    cin.imbue(locale(cin.getloc(), new colon_is_space));    string word;   while(cin >> word) {     std::cout << word << "\n";   } } 

Answer 2

For strings, you can use the std::getline overloads to read using a different delimiter.

For number extraction, the delimiter isn't really "whitespace" to begin with, but any character invalid in a number.