Reading and throwing away input

Hey all. Quickie question. Is there a way of doing the equivalent of

Code:

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scanf("%*s");

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with cin, where you read in the input and discard it?

I assume that you mean read and discard input without creating a temporary variable. There's no easy way to do what you want, so you would just be better off creating that variable at some point, even if it's hidden behind a manipulator:

Code:

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#include <iostream>
#include <string>

std::istream& discard ( std::istream& in )
{
  std::string temp;

  return in>> temp;
}

int main()
{
  std::string word;

  for ( int i = 0; i < 3; i++ )
    std::cin>> discard;

  std::cin>> word;
  std::cout<<"The fourth word is "<< word <<std::endl;
}

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If you know how many characters you want to discard then you can use cin.ignore().

Using a std::string as temp is overkill, though.

Code:

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#include <iostream>
#include <locale>

template<typename C, typename Traits = std::char_traits<C> >
std::basic_istream<C, Traits> &discard(std::basic_istream<C, Traits> &in)
{
  typedef std::ctype<C> mytype;
  C c;
  const mytype &ct = std::use_facet<mytype>(is.getloc());
  while(in.get(c) && !ct.is(mytype::space, c)) {
  }
  return in;
}

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This ought to be faster, because it never allocates anything but stack memory.