C++ reference: istream: ws (manipulator)

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stream manipulator
istream& ws ( istream& is );

Extract whitespaces.
Extracts and discards characters from the stream as long as the next available character is a whitespace or until there are no more characters available.

Parameters.

is: Stream which extraction has to be performed to. Automatically assumed if used with extractor operator (operator>>).

Return Value.
The manipulator returns parameter is.

Example.

// whitespaces
#include <iostream>
using namespace std;

char str1[256], str2 [256];

int main () {

  cout << "Please, enter some whitespaces followed by a sentence:\n";
  cin >> ws;
  cin.getline (str1,256);

  cout << "Please, enter some whitespaces followed by a sentence:\n";
  ws (cin);
  cin.getline (str2,256);

  cout << "You wrote:" << endl << str1 << endl << str2 << endl;

  return 0;
}

This example demonstrates the two ways of calling a manipulator, both valid:
cin >> ws;
ws (cin);

Basic template declaration:

template <class charT, class traits> basic_istream<charT,traits>& ws ( basic_istream<charT,traits>& is );

See also.
istream class