I've spent the last hour and a half trying to figure out how to run a simple search and replace on a `string` object in C++.

I have three string objects.

```
string original, search_val, replace_val;

```

I want to run a search command on `original` for the `search_val` and replace all occurrences with `replace_val`.

**NB:** Answers in pure C++ only. The environment is XCode on the Mac OSX Leopard.