Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -9,10 +9,11 @@
  * the packaging of this file.
  */
 
 #import <stddef.h>
 #import "OFObject.h"
+#import "OFConstString.h"
 
 @interface OFString: OFObject
 {
 	char   *string;
 	size_t length;
@@ -21,10 +22,10 @@
 + new: (const char*)str;
 - init;
 - init: (const char*)str;
 - (char*)cString;
 - (size_t)length;
-- (OFString*)setTo: (const char*)str;
+- (OFString*)setTo: (OFConstString*)str;
 - (OFString*)clone;
-- (OFString*)append: (const char*)str;
-- (int)compare: (OFString*)str;
+- (OFString*)append: (OFConstString*)str;
+- (int)compare: (OFConstString*)str;
 @end

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -48,27 +48,27 @@
 - (size_t)length
 {
 	return length;
 }
 
-- (OFString*)setTo: (const char*)str
+- (OFString*)setTo: (OFConstString*)str
 {
 	char *newstr;
 	size_t newlen;
 	
-	if (str == NULL) {
+	if ([str cString] == NULL) {
 		[self freeMem: string];
 
 		length = 0;
 		string = NULL;
 
 		return self;
 	}
 
-	newlen = strlen(str);
+	newlen = [str length];
 	newstr = [self getMem: newlen + 1];
-	memcpy(newstr, str, newlen + 1);
+	memcpy(newstr, [str cString], newlen + 1);
 
 	if (string != NULL)
 		[self freeMem: string];
 
 	length = newlen;
@@ -80,32 +80,32 @@
 - (OFString*)clone
 {
 	return [OFString new: string];
 }
 
-- (OFString*)append: (const char*)str
+- (OFString*)append: (OFConstString*)str
 {
 	char   *newstr;
 	size_t newlen, strlength;
 
 	if (str == NULL)
-		return [self setTo:str];
+		return [self setTo: str];
 
-	strlength = strlen(str);
+	strlength = [str length];
 	newlen = length + strlength;
 
 	newstr = [self resizeMem: string
 			  toSize: newlen + 1];
 
-	memcpy(newstr + length, str, strlength + 1);
+	memcpy(newstr + length, [str cString], strlength + 1);
 
 	length = newlen;
 	string = newstr;
 
 	return self;
 }
 
-- (int)compare: (OFString*)str
+- (int)compare: (OFConstString*)str
 {
 	return strcmp(string, [str cString]);
 }
 @end

Index: src/OFWideString.h
==================================================================
--- src/OFWideString.h
+++ src/OFWideString.h
@@ -9,11 +9,13 @@
  * the packaging of this file.
  */
 
 #import <stddef.h>
 #import <wchar.h>
+
 #import "OFObject.h"
+#import "OFConstWideString.h"
 
 @interface OFWideString: OFObject
 {
 	wchar_t	*wstring;
 	size_t	length;
@@ -22,10 +24,10 @@
 + new: (const wchar_t*)wstr;
 - init;
 - init: (const wchar_t*)wstr;
 - (wchar_t*)wcString;
 - (size_t)length;
-- (OFWideString*)setTo: (const wchar_t*)wstr;
+- (OFWideString*)setTo: (OFConstWideString*)wstr;
 - (OFWideString*)clone;
-- (OFWideString*)append: (const wchar_t*)wstr;
-- (int)compare: (OFWideString*)str;
+- (OFWideString*)append: (OFConstWideString*)wstr;
+- (int)compare: (OFConstWideString*)str;
 @end

Index: src/OFWideString.m
==================================================================
--- src/OFWideString.m
+++ src/OFWideString.m
@@ -33,11 +33,11 @@
 			length = 0;
 			wstring = NULL;
 		} else {
 			length = wcslen(wstr);
 			wstring = [self getMem: (length + 1) * sizeof(wchar_t)];
-			memcpy(wstring, wstr, (length + 1) * sizeof(wchar_t));
+			wmemcpy(wstring, wstr, length + 1);
 		}
 	}
 	return self;
 }
 
@@ -49,27 +49,27 @@
 - (size_t)length
 {
 	return length;
 }
 
-- (OFWideString*)setTo: (const wchar_t*)wstr
+- (OFWideString*)setTo: (OFConstWideString*)wstr
 {
 	wchar_t *newstr;
 	size_t  newlen;
 	
-	if (wstr == NULL) {
+	if ([wstr wcString] == NULL) {
 		[self freeMem:wstring];
 
 		length = 0;
 		wstring = NULL;
 
 		return self;
 	}
 
-	newlen = wcslen(wstr);
+	newlen = [wstr length];
 	newstr = [self getMem: (newlen + 1) * sizeof(wchar_t)];
-	memcpy(newstr, wstr, (newlen + 1) * sizeof(wchar_t));
+	wmemcpy(newstr, [wstr wcString], newlen + 1);
 
 	if (wstring != NULL)
 		[self freeMem: wstring];
 
 	length = newlen;
@@ -81,32 +81,32 @@
 - (OFWideString*)clone
 {
 	return [OFWideString new: wstring];
 }
 
-- (OFWideString*)append: (const wchar_t*)wstr
+- (OFWideString*)append: (OFConstWideString*)wstr
 {
 	wchar_t	*newstr;
 	size_t	newlen, strlength;
 
-	if (wstr == NULL)
+	if ([wstr wcString] == NULL)
 		return [self setTo: wstr];
 
-	strlength = wcslen(wstr);
+	strlength = [wstr length];
 	newlen = length + strlength;
 
 	newstr = [self resizeMem: wstring
 			  toSize: (newlen + 1) * sizeof(wchar_t)];
 
-	memcpy(newstr + length, wstr, (strlength + 1) * sizeof(wchar_t));
+	wmemcpy(newstr + length, [wstr wcString], strlength + 1);
 
 	length = newlen;
 	wstring = newstr;
 
 	return self;
 }
 
-- (int)compare: (OFWideString*)str
+- (int)compare: (OFConstWideString*)str
 {
 	return wcscmp(wstring, [str wcString]);
 }
 @end

Index: tests/OFString/OFString.m
==================================================================
--- tests/OFString/OFString.m
+++ tests/OFString/OFString.m
@@ -22,30 +22,30 @@
 	OFString *s1 = [OFString new: "test"];
 	OFString *s2 = [[OFString alloc] init: ""];
 	OFString *s3;
 	OFString *s4 = [OFString new];
 
-	[s2 append: "123"];
+	[s2 append: [OFConstString new: "123"]];
 	s3 = [s1 clone];
 
-	[s4 setTo: [s2 cString]];
+	[s4 setTo: (OFConstString*)s2];
 
-	if (![s1 compare: s3])
+	if (![s1 compare: (OFConstString*)s3])
 		puts("s1 and s3 match! GOOD!");
 	else {
 		puts("s1 and s3 don't match!");
 		return 1;
 	}
 
-	if (![s2 compare: s4])
+	if (![s2 compare: (OFConstString*)s4])
 		puts("s2 and s4 match! GOOD!");
 	else {
 		puts("s1 and s3 don't match!");
 		return 1;
 	}
 
-	if (!strcmp([[s1 append: [s2 cString]] cString], "test123"))
+	if (!strcmp([[s1 append: (OFConstString*)s2] cString], "test123"))
 		puts("s1 appended with s2 is the expected string! GOOD!");
 	else {
 		puts("s1 appended with s2 is not the expected string!");
 		return 1;
 	}

Index: tests/OFWideString/OFWideString.m
==================================================================
--- tests/OFWideString/OFWideString.m
+++ tests/OFWideString/OFWideString.m
@@ -21,30 +21,30 @@
 	OFWideString *s1 = [OFWideString new: L"test"];
 	OFWideString *s2 = [[OFWideString alloc] init: L""];
 	OFWideString *s3;
 	OFWideString *s4 = [OFWideString new];
 
-	[s2 append: L"123"];
+	[s2 append: [OFConstWideString new: L"123"]];
 	s3 = [s1 clone];
 
-	[s4 setTo: [s2 wcString]];
+	[s4 setTo: (OFConstWideString*)s2];
 
-	if (![s1 compare: s3])
+	if (![s1 compare: (OFConstWideString*)s3])
 		puts("s1 and s3 match! GOOD!");
 	else {
 		puts("s1 and s3 don't match!");
 		return 1;
 	}
 
-	if (![s2 compare: s4])
+	if (![s2 compare: (OFConstWideString*)s4])
 		puts("s2 and s4 match! GOOD!");
 	else {
 		puts("s1 and s3 don't match!");
 		return 1;
 	}
 
-	if (!wcscmp([[s1 append: [s2 wcString]] wcString], L"test123"))
+	if (!wcscmp([[s1 append: (OFConstWideString*)s2] wcString], L"test123"))
 		puts("s1 appended with s2 is the expected string! GOOD!");
 	else {
 		puts("s1 appended with s2 is not the expected string!");
 		return 1;
 	}