Trimming internal whitespace in std::string

Question

I'm looking for an elegant way to transform an std::string from something like:

std::string text = "   a\t   very  \t   ugly   \t\t\t\t   string       ";

To:

std::string text = "a very ugly string";

I've already trimmed the external whitespace with boost::trim(text);

[edit] Thus, multiple whitespaces, and tabs, are reduced to just one space [/edit]

Removing the external whitespace is trivial. But is there an elegant way of removing the internal whitespace that doesn't involve manual iteration and comparison of previous and next characters? Perhaps something in boost I have missed?

Answer 1

You can use std::unique with std::remove along with ::isspace to compress multiple whitespace characters into single spaces:

std::remove(std::unique(std::begin(text), std::end(text), [](char c, char c2) {
    return ::isspace(c) && ::isspace(c2);
}), std::end(text));

Answer 2

std::istringstream iss(text);
text = "";
std::string s;
while(iss >> s){
     if ( text != "" ) text += " " + s;
     else text = s;
}
//use text, extra whitespaces are removed from it