Remove BStringRef and users.

As discussed in 2008
(http://www.freelists.org/post/haiku-development/BString-on-GCC4,1),
this class was not efficient because of lack of inlining. Implement the
suggested solution of a SetCharAt method instead. Also add a CompareAt
which covers a specific use case in KeyboardLayout.cpp.

Adjust all places which were using this feature to safer APIs.

Also fixes a copypaste error in FormattingConventions.cpp.

headers/os/support/String.h

@@ -183,6 +183,9 @@ public:
 			int				Compare(const BString& string, int32 length) const;
 			int				Compare(const char* string, int32 length) const;
 
+			int				CompareAt(size_t offset, const BString& string,
+								int32 length) const;
+
 			int				CompareChars(const BString& string,
 								int32 charCount) const;
 			int				CompareChars(const char* string,
@@ -293,9 +296,7 @@ public:
 			// Unchecked char access
 			char			operator[](int32 index) const;
 
-#if __GNUC__ > 3
+#if __GNUC__ == 2
-			BStringRef		operator[](int32 index);
-#else
 			char&			operator[](int32 index);
 #endif
 
@@ -308,6 +309,7 @@ public:
 			// Fast low-level manipulation
 			char*			LockBuffer(int32 maxLength);
 			BString&		UnlockBuffer(int32 length = -1);
+			BString&		SetCharAt(int32 pos, char to);
 
 			// Upercase <-> Lowercase
 			BString&		ToLower();
@@ -350,7 +352,6 @@ public:
 
 private:
 			class PosVect;
-			friend class BStringRef;
 
 			enum PrivateDataTag {
 				PRIVATE_DATA
@@ -604,26 +605,4 @@ operator!=(const char* str, const BString& string)
 }
 
 
-//	#pragma mark - BStringRef
-
-
-class BStringRef {
-public:
-	BStringRef(BString& string, int32 position);
-	~BStringRef() {}
-
-	operator char() const;
-
-	char* operator&();
-	const char* operator&() const;
-
-	BStringRef& operator=(char c);
-	BStringRef& operator=(const BStringRef& rc);
-
-private:
-	BString&	fString;
-	int32		fPosition;
-};
-
-
 #endif	// _B_STRING_H

src/apps/deskcalc/ExpressionTextView.cpp

@@ -288,13 +288,13 @@ ExpressionTextView::SetValue(BString value)
 				if (digit != 10)
 					break;
 
-				value[offset] = '0';
+				value.SetCharAt(offset, '0');
 			}
 			if (digit == 10) {
 				// carry over, shift the result
 				if (value[firstDigit + 1] == '.') {
-					value[firstDigit + 1] = '0';
+					value.SetCharAt(firstDigit + 1, '0');
-					value[firstDigit] = '.';
+					value.SetCharAt(firstDigit, '.');
 				}
 				value.Insert('1', 1, firstDigit);
 
@@ -311,7 +311,7 @@ ExpressionTextView::SetValue(BString value)
 				value << 'E' << exponent;
 			} else {
 				// increase the current digit value with one
-				value[offset] = char(digit + 48);
+				value.SetCharAt(offset, char(digit + 48));
 
 				// set offset to last digit
 				offset = value.FindFirst('E');

src/apps/webpositive/BrowserWindow.cpp

@@ -2435,7 +2435,7 @@ BrowserWindow::_EncodeURIComponent(const BString& search)
 	for (int32 i = 0; i < result.Length(); i++) {
 		if (escCharList.FindFirst(result[i]) != B_ERROR) {
 			sprintf(hexcode, "%02X", (unsigned int)result[i]);
-			result[i] = '%';
+			result.SetCharAt(i, '%');
 			result.Insert(hexcode, i + 1);
 			i += 2;
 		}

src/kits/locale/FormattingConventions.cpp

@@ -212,7 +212,7 @@ BFormattingConventions::BFormattingConventions(
 
 		for (int t = 0; t < B_TIME_FORMAT_STYLE_COUNT; ++t) {
 			fCachedDateTimeFormats[s][t] = other.fCachedDateFormats[s][t];
-			fExplicitDateFormats[s][t] = other.fExplicitDateFormats[s][t];
+			fExplicitDateTimeFormats[s][t] = other.fExplicitDateFormats[s][t];
 		}
 	}
 	for (int s = 0; s < B_TIME_FORMAT_STYLE_COUNT; ++s) {

src/kits/mail/HaikuMailFormatFilter.cpp

@@ -247,7 +247,7 @@ HaikuMailFormatFilter::_RemoveExtraWhitespace(BString& name)
 			if (i == remove + 1 || i == name.Length())
 				remove++;
 			else
-				name[i - spaces] = ' ';
+				name.SetCharAt(i - spaces, ' ');
 			name.Remove(i - remove, remove);
 			i -= remove;
 			spaces = 0;

src/kits/support/String.cpp

@@ -132,57 +132,6 @@ private:
 };
 
 
-//	#pragma mark - BStringRef
-
-
-BStringRef::BStringRef(BString& string, int32 position)
-	:
-	fString(string), fPosition(position)
-{
-}
-
-
-BStringRef::operator char() const
-{
-	return fPosition < fString.Length() ? fString.fPrivateData[fPosition] : 0;
-}
-
-
-BStringRef&
-BStringRef::operator=(char c)
-{
-	fString._MakeWritable();
-	fString.fPrivateData[fPosition] = c;
-	return *this;
-}
-
-
-BStringRef&
-BStringRef::operator=(const BStringRef &rc)
-{
-	return operator=(rc.fString.fPrivateData[rc.fPosition]);
-}
-
-
-const char*
-BStringRef::operator&() const
-{
-	return &fString.fPrivateData[fPosition];
-}
-
-
-char*
-BStringRef::operator&()
-{
-	if (fString._MakeWritable() != B_OK)
-		return NULL;
-
-	fString._ReferenceCount() = -1;
-		// mark as unsharable
-	return &fString.fPrivateData[fPosition];
-}
-
-
 //	#pragma mark - BString
 
 
@@ -1109,6 +1058,13 @@ BString::Compare(const char* string, int32 length) const
 }
 
 
+int
+BString::CompareAt(size_t offset, const BString& string, int32 length) const
+{
+	return strncmp(String() + offset, string.String(), length);
+}
+
+
 int
 BString::CompareChars(const BString& string, int32 charCount) const
 {
@@ -1866,13 +1822,7 @@ BString::ReplaceCharsSet(const char* setOfChars, const char* with)
 //	#pragma mark - Unchecked char access
 
 
-#if __GNUC__ > 3
+#if __GNUC__ == 2
-BStringRef
-BString::operator[](int32 index)
-{
-	return BStringRef(*this, index);
-}
-#else
 char&
 BString::operator[](int32 index)
 {
@@ -1953,6 +1903,16 @@ BString::UnlockBuffer(int32 length)
 }
 
 
+BString&
+BString::SetCharAt(int32 pos, char to)
+{
+	if (pos < Length() && _MakeWritable() == B_OK)
+		fPrivateData[pos] = to;
+
+	return *this;
+}
+
+
 //	#pragma mark - Uppercase <-> Lowercase
 
 

src/preferences/keymap/KeyboardLayout.cpp

@@ -710,7 +710,7 @@ KeyboardLayout::_SubstituteVariables(BString& term, VariableMap& variables,
 
 		for (; iterator != variables.end(); iterator++) {
 			const BString& name = iterator->first;
-			if (!name.Compare(&term[index], name.Length())
+			if (!term.CompareAt(index, name, name.Length())
 				&& name.Length() > bestLength) {
 				best = iterator;
 				bestLength = name.Length();
@@ -723,12 +723,11 @@ KeyboardLayout::_SubstituteVariables(BString& term, VariableMap& variables,
 			term.Insert(best->second.String(), index);
 		} else {
 			// variable has not been found
-			unknown = &term[index];
 			int32 length = 1;
-			while (isalpha(unknown[length])) {
+			while (isalpha(term[length + index])) {
 				length++;
 			}
-			unknown.Truncate(length);
+			term.Truncate(length + index);
 			return false;
 		}
 	}

src/preferences/mail/DNSQuery.cpp

@@ -229,14 +229,14 @@ DNSTools::ConvertToDNSName(const BString& string)
 
 			// set a counts to the dot
 			diff =  dot - 1 - lastDot;
-			outString[lastDot] = (char)diff;
+			outString.SetCharAt(lastDot, (char)diff);
 			lastDot = dot;
 		}
 	} else
 		lastDot = 0;
 
 	diff = outString.CountChars() - 1 - lastDot;
-	outString[lastDot] = (char)diff;
+	outString.SetCharAt(lastDot, (char)diff);
 
 	return outString;
 }
@@ -259,7 +259,7 @@ DNSTools::ConvertFromDNSName(const BString& string)
 		if (dot == 0)
 			break;
 		// set a "."
-		outString[nextDot] = '.';
+		outString.SetCharAt(nextDot, '.');
 		nextDot+= dot + 1;
 	}
 	return outString;