comparison DEPENDENCIES/generic/include/boost/xpressive/detail/utility/width.hpp @ 16:2665513ce2d3

Add boost headers

+///////////////////////////////////////////////////////////////////////////////
+// width.hpp
+//
+//  Copyright 2008 Eric Niebler. Distributed under 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_XPRESSIVE_DETAIL_UTILITY_WIDTH_HPP_EAN_04_07_2006
+#define BOOST_XPRESSIVE_DETAIL_UTILITY_WIDTH_HPP_EAN_04_07_2006
+
+// MS compatible compilers support #pragma once
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+#include <climits> // for INT_MAX
+#include <boost/mpl/size_t.hpp>
+
+namespace boost { namespace xpressive { namespace detail
+{
+
+typedef mpl::size_t<INT_MAX / 2 - 1> unknown_width;
+struct width;
+bool is_unknown(width const &that);
+
+///////////////////////////////////////////////////////////////////////////////
+// width
+struct width
+{
+    width(std::size_t val = 0)
+      : value_(val)
+    {
+    }
+
+    bool operator !() const
+    {
+        return !this->value_;
+    }
+
+    width &operator +=(width const &that)
+    {
+        this->value_ =
+            !is_unknown(*this) && !is_unknown(that)
+          ? this->value_ + that.value_
+          : unknown_width();
+        return *this;
+    }
+
+    width &operator |=(width const &that)
+    {
+        this->value_ =
+            this->value_ == that.value_
+          ? this->value_
+          : unknown_width();
+        return *this;
+    }
+
+    std::size_t value() const
+    {
+        return this->value_;
+    }
+
+private:
+    std::size_t value_;
+};
+
+inline bool is_unknown(width const &that)
+{
+    return unknown_width::value == that.value();
+}
+
+inline bool operator ==(width const &left, width const &right)
+{
+    return left.value() == right.value();
+}
+
+inline bool operator !=(width const &left, width const &right)
+{
+    return left.value() != right.value();
+}
+
+inline width operator +(width left, width const &right)
+{
+    return left += right;
+}
+
+inline width operator |(width left, width const &right)
+{
+    return left |= right;
+}
+
+}}} // namespace boost::xpressive::detail
+
+#endif