title: Replace char in string with some string inplace
body: <p><br>i want to replace a character in the string with a string. can i do it in-place? As the new string has length greater than original string.Question is that can i do with using additional buffer?
  for example</p>
  
  <pre><code>void replaceChar(std::string &amp;input, std::string replacementString, char charToReplace)
  {
  //some code here. No additional buffer
  }
  
  void main(){
  
    std::string input = "I am posting a comment on LinkedIn";
    std::string replacementString = "pppp";
    char charToReplace = 'o';
    replaceChar(input, replacementString, charToReplace);
  }
  </code></pre>
  
  <p>I only want the strategy (algorithm). it would be good if algorithm will be designed keeping some language in mind that will not dynamically increase or decrease the string length once it was initilized like c++</p>