skipws


manipulator function
<ios>
ios_base& skipws ( ios_base& str );

Skip whitespaces

Sets the skipws format flag for the str stream.

When the skipws format flag is set, as many whitespace characters as necessary are read and discarded from the stream until a non-whitespace character is found before every extraction operation. Tab spaces, carriage returns and blank spaces are all considered whitespaces.

This flag can be unset with the noskipws manipulator, forcing extraction operations to consider leading whitepaces as part of the content to be extracted.

The skipws flag is set in standard streams on initialization.

Parameters

str
Stream object where to apply.
Because this function is a manipulator, it is designed to be used alone with no arguments in conjunction with the insertion (<<) and extraction (>>) operations on streams (see example below).


Return Value

A reference to the stream object.

Example

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// skipws flag example
#include <iostream>
#include <sstream>
using namespace std;

int main () {
  char a, b, c;

  istringstream iss ("  123");
  iss >> skipws >> a >> b >> c;
  cout << a << b << c << endl;

  iss.seekg(0);
  iss >> noskipws >> a >> b >> c;
  cout << a << b << c << endl;
  return 0;
}


The execution of this example displays something similar to:
123
  1

Notice that in the first set of extractions, the leading spaces were ignored, while in the second they were extracted as regular characters.

See also