I have some parsing code that allows for escape sequences to be entered into a string of text:

```
// In a file or large, multi-line string ...
my_parameter="A setting for the parameter\nthat contains \"escape sequence\" characters"

```

When I parse it, I handle the backslashes and add the appropriate character to the string that I am building using a `std::ostringstream` instance. Line feeds, quotes, backslashes and such all work fine. However, I was contemplating whether or not to allow the `\b` sequence, and went looking to see if I can "unput" the last character from my `ostringstream` like you can "unget" from any `std::istream`. Can you do such a thing? If the function does not exist, is there a simple way to push the write position back one character and simply have the next character read overwrite it?

This is not mission-critical or anything like that, but I was curious if anyone else has come across this before.