-/* $Id$
-
-This file is part of libmspstrings
-Copyright © 2006-2008 Mikko Rasa
-Distributed under the LGPL
-*/
-
#ifndef MSP_STRINGS_LEXICALCAST_H_
#define MSP_STRINGS_LEXICALCAST_H_
#include <sstream>
#include <string>
-#include <msp/core/except.h>
+#include <stdexcept>
+#include <msp/core/meta.h>
+#include <msp/core/mspcore_api.h>
#include "fmt.h"
namespace Msp {
/**
-Thrown for errors in lexical conversions
+Thrown for errors in lexical conversions.
+*/
+class MSPCORE_API lexical_error: public std::runtime_error
+{
+public:
+ lexical_error(const std::string &w): runtime_error(w) { }
+};
+
+
+/**
+Thrown when the format is unsuitable for the type being converted.
*/
-class LexicalError: public Exception
+class MSPCORE_API format_mismatch: public lexical_error
{
public:
- LexicalError(const std::string &w_): Exception(w_) { }
+ format_mismatch(const std::string &w): lexical_error(w) { }
};
/**
Helper class for lexical_cast to facilitate operator overloading.
*/
-class LexicalConverter
+class MSPCORE_API LexicalConverter
{
private:
Fmt fmt;
+ bool filled = false;
std::string buf;
public:
LexicalConverter(const Fmt &f): fmt(f) { }
- LexicalConverter(const std::string &s, const Fmt &f): fmt(f), buf(s) { }
+ LexicalConverter(const std::string &s, const Fmt &f): fmt(f), filled(true), buf(s) { }
const Fmt &get_fmt() const { return fmt; }
- const std::string &get() const { return buf; }
+ const std::string &get() const;
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 &);
+MSPCORE_API void operator<<(LexicalConverter &, char);
+MSPCORE_API void operator<<(LexicalConverter &, signed char);
+MSPCORE_API void operator<<(LexicalConverter &, short);
+MSPCORE_API void operator<<(LexicalConverter &, int);
+MSPCORE_API void operator<<(LexicalConverter &, long);
+MSPCORE_API void operator<<(LexicalConverter &, unsigned char);
+MSPCORE_API void operator<<(LexicalConverter &, unsigned short);
+MSPCORE_API void operator<<(LexicalConverter &, unsigned);
+MSPCORE_API void operator<<(LexicalConverter &, unsigned long);
+MSPCORE_API void operator<<(LexicalConverter &, long long);
+MSPCORE_API void operator<<(LexicalConverter &, unsigned long long);
+MSPCORE_API void operator<<(LexicalConverter &, bool);
+MSPCORE_API void operator<<(LexicalConverter &, float);
+MSPCORE_API void operator<<(LexicalConverter &, double);
+MSPCORE_API void operator<<(LexicalConverter &, long double);
+MSPCORE_API void operator<<(LexicalConverter &, const std::string &);
+MSPCORE_API void operator<<(LexicalConverter &, const char *);
+MSPCORE_API void operator<<(LexicalConverter &, const void *);
+
+MSPCORE_API void operator>>(const LexicalConverter &, char &);
+MSPCORE_API void operator>>(const LexicalConverter &, signed char &);
+MSPCORE_API void operator>>(const LexicalConverter &, short &);
+MSPCORE_API void operator>>(const LexicalConverter &, int &);
+MSPCORE_API void operator>>(const LexicalConverter &, long &);
+MSPCORE_API void operator>>(const LexicalConverter &, unsigned char &);
+MSPCORE_API void operator>>(const LexicalConverter &, unsigned short &);
+MSPCORE_API void operator>>(const LexicalConverter &, unsigned int &);
+MSPCORE_API void operator>>(const LexicalConverter &, unsigned long &);
+MSPCORE_API void operator>>(const LexicalConverter &, long long &);
+MSPCORE_API void operator>>(const LexicalConverter &, unsigned long long &);
+MSPCORE_API void operator>>(const LexicalConverter &, bool &);
+MSPCORE_API void operator>>(const LexicalConverter &, float &);
+MSPCORE_API void operator>>(const LexicalConverter &, double &);
+MSPCORE_API void operator>>(const LexicalConverter &, long double &);
+MSPCORE_API void operator>>(const LexicalConverter &, std::string &);
// Generic operators using stringstream
+struct CheckFormattedOutput: Sfinae
+{
+ static std::ostream &s;
+ template<typename T>
+ static Yes f(int (*)[sizeof(s<<reinterpret_cast<const T &>(s))]);
+ using Sfinae::f;
+};
+
+struct CheckFormattedInput: Sfinae
+{
+ static std::istream &s;
+ template<typename T>
+ static Yes f(int (*)[sizeof(s>>reinterpret_cast<T &>(s))]);
+ using Sfinae::f;
+};
+
+template<typename T> struct HasFormattedOutput: Sfinae::Evaluate<CheckFormattedOutput, T> { };
+template<typename T> struct HasFormattedInput: Sfinae::Evaluate<CheckFormattedInput, T> { };
+
+
template<typename T>
-void operator<<(LexicalConverter &c, const T &v)
+typename std::enable_if<HasFormattedOutput<T>::value>::type
+operator<<(LexicalConverter &c, const T &v)
{
std::ostringstream ss;
- ss<<c.get_fmt()<<v;
+ ss << c.get_fmt() << v;
c.result(ss.str());
}
template<typename T>
-void operator>>(const LexicalConverter &c, T &v)
+typename std::enable_if<HasFormattedInput<T>::value>::type
+operator>>(const LexicalConverter &c, T &v)
{
std::istringstream ss(c.get());
ss.setf(std::ios_base::fmtflags(0), std::ios_base::skipws);
- ss>>v;
+ ss >> v;
if(ss.fail() || !ss.eof())
- throw LexicalError("Conversion failure");
+ throw lexical_error("conversion failure");
}
-// The main interface to the lexical conversion machinery
+/**
+Helper struct to provide partial template specialization.
+*/
+template<typename T, typename F>
+struct LexicalCast;
template<typename T>
-inline T lexical_cast(const std::string &s, const Fmt &f = Fmt())
+struct LexicalCast<T, std::string>
{
- LexicalConverter conv(s, f);
- T result;
- conv>>result;
- return result;
-}
+ static T cast(const std::string &s, const Fmt &f = Fmt())
+ {
+ LexicalConverter conv(s, f);
+ T result;
+ conv >> result;
+ return result;
+ }
+};
-template<typename T>
-inline std::string lexical_cast(const T &v, const Fmt &f = Fmt())
+template<typename F>
+struct LexicalCast<std::string, F>
+{
+ static std::string cast(const F &v, const Fmt &f = Fmt())
+ {
+ LexicalConverter conv(f);
+ conv << v;
+ return conv.get();
+ }
+};
+
+template<>
+struct LexicalCast<std::string, std::string>
+{
+ static std::string cast(const std::string &v, const Fmt &f = Fmt())
+ {
+ LexicalConverter conv(f);
+ conv << v;
+ return conv.get();
+ }
+};
+
+/** Perform a lexical conversion between a string and another type. The source
+type can normally be deduced by the compiler, so this can be used just like the
+standard C++ casts. A format may additionally be specified to force a specific
+interpretation. */
+template<typename T, typename F>
+inline T lexical_cast(const F &v, const Fmt &f = Fmt())
{
- LexicalConverter conv(f);
- conv<<v;
- return conv.get();
+ return LexicalCast<T, F>::cast(v, f);
}
} // namespace Msp
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