trim and tokenize

util.cpp

using namespace std;

vector<string> tokenize(string const &line, char separator) {
	vector<string> tokens;
	istringstream elements(line);
	while(!elements.eof()) {
		string token;
		getline(elements, token, separator);
		tokens.push_back(token);
	}
	return tokens;
}

namespace {

	void skipTrailingWS( string::const_iterator const & leading, string::const_iterator& trailing, string const &aString ) 
	{
		while(trailing != leading && *--trailing == ' ') ;
		if(trailing != aString.end() && trailing != aString.begin()) ++trailing;
	}

	void skipLeadingWS( string::const_iterator& leading, string::const_iterator const & trailing ) 
	{
		while(leading != trailing && *leading == ' ') ++leading;
	}

}

string trim(string const &aString) {

	string::const_iterator trailing = aString.end();
	string::const_iterator leading = aString.begin();

	skipTrailingWS(leading, trailing, aString);

	skipLeadingWS(leading, trailing);

	ostringstream out;
	while(leading != trailing) out << *leading++;
	return out.str();
}

// Gtest tests

TEST(UtilTest, TrimmingAStringWithoutLeadingOrTrailingWhitespaceIsNoop) 
{
	std::string nothingToTrim = "no leading or trailing whitespace";

	ASSERT_EQ(nothingToTrim, trim(nothingToTrim));
}

TEST(UtilTest, TrimmingAStringRemovesLeadingWhitespace) 
{
	std::string leadingWhitespace = "    leading whitespace";
	std::string trimmed = "leading whitespace";

	ASSERT_EQ(trimmed, trim(leadingWhitespace));
}

TEST(UtilTest, TrimmingAStringRemovesTrailingWhitespace) 
{
	std::string trailingWhitespace = "trailing whitespace   ";
	std::string trimmed = "trailing whitespace";

	ASSERT_EQ(trimmed, trim(trailingWhitespace));
}

TEST(UtilTest, TrimmingAStringWithOnlySpaceYieldsEmptyString) 
{
	std::string onlyWhitespace = "      ";
	std::string trimmed = "";

	ASSERT_EQ(trimmed, trim(onlyWhitespace));
}