Counting all words in a file
Let's say we read a text file and we want to count the number of words in the text. We define that one word is a range of characters between whitespace characters. How do we do it?
We could count the number of spaces, for example, because there must be spaces between words. In the sentence, "John has a funny little dog.", we have five space characters, so we could say there are six words.
What if we have a sentence with whitespace noise, such as " John has \t a\nfunny little dog ."? There are way too many unnecessary spaces in this string, and it's not even only spaces. From the other recipes in this book, we already learned how we can remove such excess whitespace. So, we could first preprocess the string into a normal sentence form and then apply the strategy of counting space characters. Yes, that is doable, but there is a much easier way. Why shouldn't we use what the STL already provides us?
In addition to finding an elegant solution for this problem, we will...
