comparison DEPENDENCIES/generic/include/boost/logic/tribool_io.hpp @ 16:2665513ce2d3

Add boost headers

+// Three-state boolean logic library
+
+// Copyright Douglas Gregor 2002-2004. Use, modification and
+// distribution is subject to the Boost Software License, Version
+// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#ifndef BOOST_LOGIC_TRIBOOL_IO_HPP
+#define BOOST_LOGIC_TRIBOOL_IO_HPP
+
+#include <boost/logic/tribool.hpp>
+#include <boost/detail/workaround.hpp>
+#include <boost/noncopyable.hpp>
+
+#if BOOST_WORKAROUND(_MSC_VER, >= 1200)
+#  pragma once
+#endif
+
+#ifndef BOOST_NO_STD_LOCALE
+#  include <locale>
+#endif
+
+#include <string>
+#include <iostream>
+
+namespace boost { namespace logic {
+
+#ifdef BOOST_NO_STD_LOCALE
+
+/**
+ * \brief Returns a string containing the default name for the \c
+ * false value of a tribool with the given character type T.
+ *
+ * This function only exists when the C++ standard library
+ * implementation does not support locales.
+ */
+template<typename T> std::basic_string<T> default_false_name();
+
+/**
+ * \brief Returns the character string "false".
+ *
+ * This function only exists when the C++ standard library
+ * implementation does not support locales.
+ */
+template<>
+inline std::basic_string<char> default_false_name<char>()
+{ return "false"; }
+
+#  ifndef BOOST_NO_WCHAR_T
+/**
+ * \brief Returns the wide character string L"false".
+ *
+ * This function only exists when the C++ standard library
+ * implementation does not support locales.
+ */
+template<>
+inline std::basic_string<wchar_t> default_false_name<wchar_t>()
+{ return L"false"; }
+#  endif
+
+/**
+ * \brief Returns a string containing the default name for the \c true
+ * value of a tribool with the given character type T.
+ *
+ * This function only exists when the C++ standard library
+ * implementation does not support locales.
+ */
+template<typename T> std::basic_string<T> default_true_name();
+
+/**
+ * \brief Returns the character string "true".
+ *
+ * This function only exists when the C++ standard library
+ * implementation does not support locales.
+ */
+template<>
+inline std::basic_string<char> default_true_name<char>()
+{ return "true"; }
+
+#  ifndef BOOST_NO_WCHAR_T
+/**
+ * \brief Returns the wide character string L"true".
+ *
+ *  This function only exists * when the C++ standard library
+ *  implementation does not support * locales.
+ */
+template<>
+inline std::basic_string<wchar_t> default_true_name<wchar_t>()
+{ return L"true"; }
+#  endif
+#endif
+
+/**
+ * \brief Returns a string containing the default name for the indeterminate
+ * value of a tribool with the given character type T.
+ *
+ * This routine is used by the input and output streaming operators
+ * for tribool when there is no locale support or the stream's locale
+ * does not contain the indeterminate_name facet.
+ */
+template<typename T> std::basic_string<T> get_default_indeterminate_name();
+
+/// Returns the character string "indeterminate".
+template<>
+inline std::basic_string<char> get_default_indeterminate_name<char>()
+{ return "indeterminate"; }
+
+#if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
+// VC++ 6.0 chokes on the specialization below, so we're stuck without 
+// wchar_t support. What a pain. TODO: it might just need a the template 
+// parameter as function parameter...
+#else
+#  ifndef BOOST_NO_WCHAR_T
+/// Returns the wide character string L"indeterminate".
+template<>
+inline std::basic_string<wchar_t> get_default_indeterminate_name<wchar_t>()
+{ return L"indeterminate"; }
+#  endif
+#endif
+
+// http://www.cantrip.org/locale.html
+
+#ifndef BOOST_NO_STD_LOCALE
+/**
+ * \brief A locale facet specifying the name of the indeterminate
+ * value of a tribool.
+ *
+ * The facet is used to perform I/O on tribool values when \c
+ * std::boolalpha has been specified. This class template is only
+ * available if the C++ standard library implementation supports
+ * locales.
+ */
+template<typename CharT>
+class indeterminate_name : public std::locale::facet, private boost::noncopyable
+{
+public:
+  typedef CharT char_type;
+  typedef std::basic_string<CharT> string_type;
+
+  /// Construct the facet with the default name
+  indeterminate_name() : name_(get_default_indeterminate_name<CharT>()) {}
+
+  /// Construct the facet with the given name for the indeterminate value
+  explicit indeterminate_name(const string_type& initial_name)
+  : name_(initial_name) {}
+
+  /// Returns the name for the indeterminate value
+  string_type name() const { return name_; }
+
+  /// Uniquily identifies this facet with the locale.
+  static std::locale::id id;
+
+private:
+  string_type name_;
+};
+
+template<typename CharT> std::locale::id indeterminate_name<CharT>::id;
+#endif
+
+/**
+ * \brief Writes the value of a tribool to a stream.
+ *
+ * When the value of @p x is either \c true or \c false, this routine
+ * is semantically equivalent to:
+ * \code out << static_cast<bool>(x); \endcode
+ *
+ * When @p x has an indeterminate value, it outputs either the integer
+ * value 2 (if <tt>(out.flags() & std::ios_base::boolalpha) == 0</tt>)
+ * or the name of the indeterminate value. The name of the
+ * indeterminate value comes from the indeterminate_name facet (if it
+ * is defined in the output stream's locale), or from the
+ * get_default_indeterminate_name function (if it is not defined in the
+ * locale or if the C++ standard library implementation does not
+ * support locales).
+ *
+ * \returns @p out
+ */
+template<typename CharT, typename Traits>
+inline std::basic_ostream<CharT, Traits>&
+operator<<(std::basic_ostream<CharT, Traits>& out, tribool x)
+{
+  if (!indeterminate(x)) {
+    out << static_cast<bool>(x);
+  } else {
+    typename std::basic_ostream<CharT, Traits>::sentry cerberus(out);
+    if (cerberus) {
+      if (out.flags() & std::ios_base::boolalpha) {
+#ifndef BOOST_NO_STD_LOCALE
+        if (BOOST_HAS_FACET(indeterminate_name<CharT>, out.getloc())) {
+          const indeterminate_name<CharT>& facet =
+            BOOST_USE_FACET(indeterminate_name<CharT>, out.getloc());
+          out << facet.name();
+        } else {
+          out << get_default_indeterminate_name<CharT>();
+        }
+#else
+        out << get_default_indeterminate_name<CharT>();
+#endif
+      }
+      else
+        out << 2;
+    }
+  }
+  return out;
+}
+
+/**
+ * \brief Writes the indeterminate tribool value to a stream.
+ *
+ * This routine outputs either the integer
+ * value 2 (if <tt>(out.flags() & std::ios_base::boolalpha) == 0</tt>)
+ * or the name of the indeterminate value. The name of the
+ * indeterminate value comes from the indeterminate_name facet (if it
+ * is defined in the output stream's locale), or from the
+ * get_default_indeterminate_name function (if it is not defined in the
+ * locale or if the C++ standard library implementation does not
+ * support locales).
+ *
+ * \returns @p out
+ */
+template<typename CharT, typename Traits>
+inline std::basic_ostream<CharT, Traits>&
+operator<<(std::basic_ostream<CharT, Traits>& out, 
+           bool (*)(tribool, detail::indeterminate_t))
+{ return out << tribool(indeterminate); } 
+
+/**
+ * \brief Reads a tribool value from a stream.
+ *
+ * When <tt>(out.flags() & std::ios_base::boolalpha) == 0</tt>, this
+ * function reads a \c long value from the input stream @p in and
+ * converts that value to a tribool. If that value is 0, @p x becomes
+ * \c false; if it is 1, @p x becomes \c true; if it is 2, @p becomes
+ * \c indetermine; otherwise, the operation fails (and the fail bit is
+ * set on the input stream @p in).
+ *
+ * When <tt>(out.flags() & std::ios_base::boolalpha) != 0</tt>, this
+ * function first determines the names of the false, true, and
+ * indeterminate values. The false and true names are extracted from
+ * the \c std::numpunct facet of the input stream's locale (if the C++
+ * standard library implementation supports locales), or from the \c
+ * default_false_name and \c default_true_name functions (if there is
+ * no locale support). The indeterminate name is extracted from the
+ * appropriate \c indeterminate_name facet (if it is available in the
+ * input stream's locale), or from the \c get_default_indeterminate_name
+ * function (if the C++ standard library implementation does not
+ * support locales, or the \c indeterminate_name facet is not
+ * specified for this locale object). The input is then matched to
+ * each of these names, and the tribool @p x is assigned the value
+ * corresponding to the longest name that matched. If no name is
+ * matched or all names are empty, the operation fails (and the fail
+ * bit is set on the input stream @p in).
+ *
+ * \returns @p in
+ */
+template<typename CharT, typename Traits>
+inline std::basic_istream<CharT, Traits>&
+operator>>(std::basic_istream<CharT, Traits>& in, tribool& x)
+{
+  if (in.flags() & std::ios_base::boolalpha) {
+    typename std::basic_istream<CharT, Traits>::sentry cerberus(in);
+    if (cerberus) {
+      typedef std::basic_string<CharT> string_type;
+
+#ifndef BOOST_NO_STD_LOCALE
+      const std::numpunct<CharT>& numpunct_facet =
+        BOOST_USE_FACET(std::numpunct<CharT>, in.getloc());
+
+      string_type falsename = numpunct_facet.falsename();
+      string_type truename = numpunct_facet.truename();
+
+      string_type othername;
+      if (BOOST_HAS_FACET(indeterminate_name<CharT>, in.getloc())) {
+        othername =
+          BOOST_USE_FACET(indeterminate_name<CharT>, in.getloc()).name();
+      } else {
+        othername = get_default_indeterminate_name<CharT>();
+      }
+#else
+      string_type falsename = default_false_name<CharT>();
+      string_type truename = default_true_name<CharT>();
+      string_type othername = get_default_indeterminate_name<CharT>();
+#endif
+
+      typename string_type::size_type pos = 0;
+      bool falsename_ok = true, truename_ok = true, othername_ok = true;
+
+      // Modeled after the code from Library DR 17
+      while (falsename_ok && pos < falsename.size()
+             || truename_ok && pos < truename.size()
+             || othername_ok && pos < othername.size()) {
+        typename Traits::int_type c = in.get();
+        if (c == Traits::eof())
+          return in;
+
+        bool matched = false;
+        if (falsename_ok && pos < falsename.size()) {
+          if (Traits::eq(Traits::to_char_type(c), falsename[pos]))
+            matched = true;
+          else
+            falsename_ok = false;
+        }
+
+        if (truename_ok && pos < truename.size()) {
+          if (Traits::eq(Traits::to_char_type(c), truename[pos]))
+            matched = true;
+          else
+            truename_ok = false;
+        }
+
+        if (othername_ok && pos < othername.size()) {
+          if (Traits::eq(Traits::to_char_type(c), othername[pos]))
+            matched = true;
+          else
+            othername_ok = false;
+        }
+
+        if (matched) { ++pos; }
+        if (pos > falsename.size()) falsename_ok = false;
+        if (pos > truename.size())  truename_ok = false;
+        if (pos > othername.size()) othername_ok = false;
+      }
+
+      if (pos == 0)
+        in.setstate(std::ios_base::failbit);
+      else {
+        if (falsename_ok)      x = false;
+        else if (truename_ok)  x = true;
+        else if (othername_ok) x = indeterminate;
+        else in.setstate(std::ios_base::failbit);
+      }
+    }
+  } else {
+    long value;
+    if (in >> value) {
+      switch (value) {
+      case 0: x = false; break;
+      case 1: x = true; break;
+      case 2: x = indeterminate; break;
+      default: in.setstate(std::ios_base::failbit); break;
+      }
+    }
+  }
+
+  return in;
+}
+
+} } // end namespace boost::logic
+
+#endif // BOOST_LOGIC_TRIBOOL_IO_HPP