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#ifndef STAR_LEXICAL_CAST_HPP
#define STAR_LEXICAL_CAST_HPP
#include "StarString.hpp"
#include "StarMaybe.hpp"
#include <sstream>
#include <locale>
namespace Star {
STAR_EXCEPTION(BadLexicalCast, StarException);
// Very simple basic lexical cast using stream input. Always operates in the
// "C" locale.
template <typename Type>
Maybe<Type> maybeLexicalCast(std::string const& s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
Type result;
std::istringstream stream(s);
stream.flags(flags);
stream.imbue(std::locale::classic());
if (!(stream >> result))
return {};
// Confirm that we read everything out of the stream
char ch;
if (stream >> ch)
return {};
return result;
}
template <typename Type>
Maybe<Type> maybeLexicalCast(char const* s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
return maybeLexicalCast<Type>(std::string(s), flags);
}
template <typename Type>
Maybe<Type> maybeLexicalCast(String const& s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
return maybeLexicalCast<Type>(s.utf8(), flags);
}
template <typename Type>
Type lexicalCast(std::string const& s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
auto m = maybeLexicalCast<Type>(s, flags);
if (m)
return m.take();
else
throw BadLexicalCast(strf("Lexical cast failed on '%s'", s));
}
template <typename Type>
Type lexicalCast(char const* s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
return lexicalCast<Type>(std::string(s), flags);
}
template <typename Type>
Type lexicalCast(String const& s, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
return lexicalCast<Type>(s.utf8(), flags);
}
template <class Type>
std::string toString(Type const& t, std::ios_base::fmtflags flags = std::ios_base::boolalpha) {
std::stringstream ss;
ss.flags(flags);
ss.imbue(std::locale::classic());
ss << t;
return ss.str();
}
}
#endif
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