title: c++ use ifstream from memory
body: <p>I have some code that uses <code>ifstream</code> to read some data from a file and everything works.</p>
  
  <p>Now I wish, without modifying some code, read this data from a memory, actually I have a <code>char *</code> that contains the data...</p>
  
  <p>How can I put my <code>char *</code> data into a <code>ifstream</code> without reading effectively the file?</p>