diff --git a/src/common/String.cpp b/src/common/String.cpp
new file mode 100644
index 000000000..0dc4a3426
--- /dev/null
+++ b/src/common/String.cpp
@@ -0,0 +1,89 @@
+#include <sstream>
+#include <vector>
+#include <locale>
+#include <codecvt>
+
+#include "String.h"
+
+std::string ByteString::ConversionError::formatError(ByteString::value_type const *at, ByteString::value_type const *upto)
+{
+	std::stringstream ss;
+	ss << "Could not convert sequence to UTF-8:";
+	for(int i = 0; i < 4 && at + i < upto; i++)
+		ss << " " << std::hex << (unsigned int)std::make_unsigned<ByteString::value_type>::type(at[i]);
+	return ss.str();
+}
+
+
+std::codecvt_utf8<char32_t> convert(1);
+
+String ByteString::FromUtf8(bool ignoreError) const
+{
+	std::vector<String::value_type> destination = std::vector<String::value_type>(size(), String::value_type());
+	std::codecvt_utf8<char32_t>::state_type state;
+
+	ByteString::value_type const *from = data(), *from_next;
+	String::value_type *to = destination.data(), *to_next;
+
+	while(true)
+	{
+		std::codecvt_utf8<char32_t>::result result = convert.in(state, from, data() + size(), from_next, to, destination.data() + destination.size(), to_next);
+		from = from_next;
+		to = to_next;
+		if(result == std::codecvt_base::ok || result == std::codecvt_base::noconv)
+		{
+			destination.resize(to - destination.data());
+			return String(destination.data(), destination.size());
+		}
+		else if(result == std::codecvt_base::partial && to == destination.data() + destination.size())
+		{
+			String::value_type *old_data = destination.data();
+			destination.resize(2 * destination.size());
+			to = destination.data() + (to - old_data);
+		}
+		else
+		{
+			if(!ignoreError)
+				throw ConversionError(from, data() + size());
+
+			if(to == destination.data() + destination.size())
+			{
+				String::value_type *old_data = destination.data();
+				destination.resize(2 * destination.size());
+				to = destination.data() + (to - old_data);
+			}
+			*(to++) = std::make_unsigned<ByteString::value_type>::type(*(from++));
+		}
+	}
+}
+
+ByteString String::ToUtf8() const
+{
+	std::vector<ByteString::value_type> destination = std::vector<ByteString::value_type>(size(), ByteString::value_type());
+	std::codecvt_utf8<char32_t>::state_type state;
+
+	String::value_type const *from = data(), *from_next;
+	ByteString::value_type *to = destination.data(), *to_next;
+
+	while(true)
+	{
+		std::codecvt_utf8<char32_t>::result result = convert.out(state, from, data() + size(), from_next, to, destination.data() + destination.size(), to_next);
+		from = from_next;
+		to = to_next;
+		if(result == std::codecvt_base::ok || result == std::codecvt_base::noconv)
+		{
+			destination.resize(to - destination.data());
+			return ByteString(destination.data(), destination.size());
+		}
+		else if(result == std::codecvt_base::error)
+		{
+			throw ByteString::ConversionError(true);
+		}
+		else if(result == std::codecvt_base::partial)
+		{
+			ByteString::value_type *old_data = destination.data();
+			destination.resize(2 * destination.size());
+			to = destination.data() + (to - old_data);
+		}
+	}
+}
diff --git a/src/common/String.h b/src/common/String.h
new file mode 100644
index 000000000..2d452eae3
--- /dev/null
+++ b/src/common/String.h
@@ -0,0 +1,60 @@
+#ifndef TPT_STRING
+#define TPT_STRING
+
+#include <string>
+
+class String;
+
+class ByteString : public std::basic_string<char>
+{
+public:
+	inline ByteString(): std::basic_string<char>() {}
+	inline ByteString(size_type count, value_type ch): std::basic_string<char>(count, ch) {}
+	inline ByteString(value_type const *ch, size_type count): std::basic_string<char>(ch, count) {}
+	inline ByteString(value_type const *ch): std::basic_string<char>(ch) {}
+	template<class It> inline ByteString(It first, It last): std::basic_string<char>(first, last) {}
+	inline ByteString(ByteString const &other): std::basic_string<char>(other) {}
+	inline ByteString(ByteString &&other): std::basic_string<char>(std::move(other)) {}
+	
+	ByteString &operator=(ByteString const &other) { std::basic_string<char>::operator=(other); return *this; }
+	ByteString &operator=(ByteString &&other) { std::basic_string<char>::operator=(std::move(other)); return *this; }
+
+	class ConversionError : public std::runtime_error
+	{
+		static std::string formatError(value_type const *at, value_type const *upto);
+	public:
+		inline ConversionError(value_type const *at, value_type const *upto): std::runtime_error(formatError(at, upto)) {}
+		inline ConversionError(bool to): std::runtime_error(to ? "Could not convert to UTF-8" : "Could not convert from UTF-8") {}
+	};
+
+	String FromUtf8(bool ignoreError = true) const;
+	inline String FromAscii() const;
+};
+
+class String : public std::basic_string<char32_t>
+{
+public:
+	inline String(): std::basic_string<char32_t>() {}
+	inline String(size_type count, value_type ch): std::basic_string<char32_t>(count, ch) {}
+	inline String(value_type const *ch, size_type count): std::basic_string<char32_t>(ch, count) {}
+	inline String(value_type const *ch): std::basic_string<char32_t>(ch) {}
+	template<class It> inline String(It first, It last): std::basic_string<char32_t>(first, last) {}
+	inline String(String const &other): std::basic_string<char32_t>(other) {}
+	inline String(String &&other): std::basic_string<char32_t>(std::move(other)) {}
+
+	String &operator=(String const &other) { std::basic_string<char32_t>::operator=(other); return *this; }
+	String &operator=(String &&other) { std::basic_string<char32_t>::operator=(std::move(other)); return *this; }
+
+	template<unsigned N> inline String(ByteString::value_type const (&ch)[N]): std::basic_string<char32_t>(ByteString(ch, N).FromAscii()) {}
+
+	ByteString ToUtf8() const;
+};
+
+inline String ByteString::FromAscii() const
+{
+	String destination = String(size(), String::value_type());
+	for(size_t i = 0; i < size(); i++)
+		destination[i] = typename String::value_type(operator[](i));
+	return destination;
+}
+#endif