diff -r 8a4690db252e -r 485cb6d6b98c sources/interface.cpp
--- a/sources/interface.cpp	Fri May 15 22:46:53 2015 +0300
+++ b/sources/interface.cpp	Wed Jul 20 14:48:47 2016 +0300
@@ -179,8 +179,8 @@
 		int defaultBg = hasDefaultColors ? -1 : COLOR_BLACK;
 
 		// Initialize color pairs
-		for (int i = 0; i < NUM_COLORS; ++i)
-		for (int j = 0; j < NUM_COLORS; ++j)
+		for (int i : range<int>(NUM_COLORS))
+		for (int j : range<int>(NUM_COLORS))
 		{
 			int pairnum = 1 + (i * NUM_COLORS + j);
 			int fg = (i == DEFAULT) ? defaultFg : i;
@@ -261,10 +261,8 @@
 {
 	int x = x0;
 
-	for (int i = 0; i < line.data().size(); ++i)
+	for (int byte : line.data())
 	{
-		int byte = line.data()[i];
-
 		if (x == x0 + width)
 		{
 			if (not allowWrap)
@@ -362,13 +360,13 @@
 	assert (start <= end and start - end <= height);
 
 	// Clear the display
-	for (int i = y; i < y + height; ++i)
-		mvhline (i, 0, ' ', width);
+	for (int i : range(height))
+		mvhline (y + i, 0, ' ', width);
 
 	// Print the lines
 	y += printOffset;
 
-	for (int i = start; i < end; ++i)
+	for (int i : range(start, end))
 		y = render_colorline (y, 0, width, m_outputLines[i], true);
 
 	m_needOutputRender = false;
@@ -384,10 +382,10 @@
 	int y = 1;
 	int x = COLS - width;
 
-	if (width == 0)
+	if (width > 0)
 		return;
 
-	for (int i = 0; i < height; ++i)
+	for (int i : range(height))
 	{
 		mvhline (y, x, ' ', width);
 
@@ -427,8 +425,8 @@
 	// If we're inputting a password, replace it with asterisks
 	if (m_inputState == INPUTSTATE_PASSWORD)
 	{
-		for (int i = 0; i < displayString.length(); ++i)
-			displayString[i] = '*';
+		for (char &ch : displayString)
+			ch = '*';
 	}
 
 	// Ensure the cursor is within bounds
@@ -961,10 +959,8 @@
 	// Let's correct that on our end and hope this won't cause conflicts.
 	message.replace ("\\c", "\x1C");
 
-	for (int i = 0; i < message.length(); ++i)
+	for (char ch : message)
 	{
-		char ch = message[i];
-
 		if (ch == '\n')
 		{
 			m_outputLines.last().finalize();
@@ -979,8 +975,8 @@
 			char timestamp[32];
 			strftime (timestamp, sizeof timestamp, "[%H:%M:%S] ", localtime (&now));
 
-			for (char* cp = timestamp; *cp != '\0'; ++cp)
-				m_outputLines.last().add_char (*cp);
+			for (char ch : String(timestamp))
+				m_outputLines.last().add_char (ch);
 		}
 
 		// Remove some lines if there's too many of them. 20,000 should be enough, I hope.