title: Standard function to replace character or substring in a char array?
body: <p>I need a function from the standard library that replaces all occurrences of a character in a string by another character.</p>
  
  <p>I also need a function from the standard library that replaces all occurrences of a substring in a string by another string.</p>
  
  <p>Are there any such functions in the standard library?</p>