/* $Id$
This file is part of libmspstrings
-Copyright © 2006-2007 Mikko Rasa
+Copyright © 2006-2008 Mikko Rasa
Distributed under the LGPL
*/
namespace Msp {
+/**
+Thrown for errors in lexical conversions
+*/
class LexicalError: public Exception
{
public:
LexicalError(const std::string &w_): Exception(w_) { }
};
-template<typename T>
-T lexical_cast(const std::string &s)
+/**
+Helper class for lexical_cast to facilitate operator overloading.
+*/
+class LexicalConverter
{
- std::istringstream ss(s);
- ss.setf(std::ios_base::fmtflags(0), std::ios_base::skipws);
+private:
+ Fmt fmt;
+ std::string buf;
- T tmp;
- ss>>tmp;
+public:
+ LexicalConverter(const Fmt &f): fmt(f) { }
+ LexicalConverter(const std::string &s, const Fmt &f): fmt(f), buf(s) { }
+
+ const Fmt &get_fmt() const { return fmt; }
+ const std::string &get() const { return buf; }
+ void result(const std::string &);
+};
+void operator<<(LexicalConverter &, char);
+void operator<<(LexicalConverter &, signed char);
+void operator<<(LexicalConverter &, short);
+void operator<<(LexicalConverter &, int);
+void operator<<(LexicalConverter &, long);
+void operator<<(LexicalConverter &, unsigned char);
+void operator<<(LexicalConverter &, unsigned short);
+void operator<<(LexicalConverter &, unsigned);
+void operator<<(LexicalConverter &, unsigned long);
+#ifdef __GNUC__
+void operator<<(LexicalConverter &, long long);
+void operator<<(LexicalConverter &, unsigned long long);
+#endif
+void operator<<(LexicalConverter &, bool);
+void operator<<(LexicalConverter &, float);
+void operator<<(LexicalConverter &, double);
+void operator<<(LexicalConverter &, long double);
+void operator<<(LexicalConverter &, const std::string &);
+void operator<<(LexicalConverter &, const char *);
+void operator<<(LexicalConverter &, const void *);
+
+void operator>>(const LexicalConverter &, char &);
+void operator>>(const LexicalConverter &, signed char &);
+void operator>>(const LexicalConverter &, short &);
+void operator>>(const LexicalConverter &, int &);
+void operator>>(const LexicalConverter &, long &);
+void operator>>(const LexicalConverter &, unsigned char &);
+void operator>>(const LexicalConverter &, unsigned short &);
+void operator>>(const LexicalConverter &, unsigned int &);
+void operator>>(const LexicalConverter &, unsigned long &);
+#ifdef __GNUC__
+void operator>>(const LexicalConverter &, long long &);
+void operator>>(const LexicalConverter &, unsigned long long &);
+#endif
+void operator>>(const LexicalConverter &, bool &);
+void operator>>(const LexicalConverter &, float &);
+void operator>>(const LexicalConverter &, double &);
+void operator>>(const LexicalConverter &, long double &);
+void operator>>(const LexicalConverter &, std::string &);
+
+// Generic operators using stringstream
+
+template<typename T>
+void operator<<(LexicalConverter &c, const T &v)
+{
+ std::ostringstream ss;
+ ss<<c.get_fmt()<<v;
+ c.result(ss.str());
+}
+
+template<typename T>
+void operator>>(const LexicalConverter &c, T &v)
+{
+ std::istringstream ss(c.get());
+ ss.setf(std::ios_base::fmtflags(0), std::ios_base::skipws);
+ ss>>v;
if(ss.fail() || !ss.eof())
throw LexicalError("Conversion failure");
+}
+
+// The main interface to the lexical conversion machinery
- return tmp;
+template<typename T>
+inline T lexical_cast(const std::string &s, const Fmt &f=Fmt())
+{
+ LexicalConverter conv(s, f);
+ T result;
+ conv>>result;
+ return result;
}
template<typename T>
-std::string lexical_cast(const T &v, const Fmt &f=Fmt())
+inline std::string lexical_cast(const T &v, const Fmt &f=Fmt())
{
- std::ostringstream ss;
- ss<<f<<v;
- return ss.str();
+ LexicalConverter conv(f);
+ conv<<v;
+ return conv.get();
}
} // namespace Msp