v1.4.4

source/core/StarLexicalCast.hpp

@@ -0,0 +1,74 @@
+#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();
+}
+
+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