Boost Tests verify text.cpp

void VerifyText(const std::wstring &text, const std::wstring expectedText)
{
	const auto pair = boost::mismatch(text, expectedText);
	const bool textEnded = (pair.first == text.end());
	const bool expectedEnded = (pair.second == expectedText.end());

	if (textEnded)
	{
		if (expectedEnded)
		{
			// No message, strings equal. Check just to ensure:
			BOOST_CHECK(text == expectedText);
		}
		else
		{
			boost::format fmt("Text is too short: got %1% bytes while %2% bytes expected");
			BOOST_ERROR((fmt % text.size() % expectedText.size()).str());
		}
	}
	else
	{
		if (expectedEnded)
		{
			boost::format fmt("Text is too long: got %1% bytes while %2% bytes expected");
			BOOST_ERROR((fmt % text.size() % expectedText.size()).str());
		}
		else
		{
			const auto distance = (pair.first - text.begin());
			const auto lineNo = 1 + std::count(text.begin(), pair.first, L'\n');
			boost::format fmt("Text mismatch at %1%-th character (%2%-th line).");
			BOOST_ERROR((fmt % distance % lineNo).str());
		}
	}
}