add boost on mac

macx64/include/boost/beast/core/string.hpp

@@ -0,0 +1,148 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// 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)
+//
+// Official repository: https://github.com/boostorg/beast
+//
+
+#ifndef BOOST_BEAST_STRING_HPP
+#define BOOST_BEAST_STRING_HPP
+
+#include <boost/beast/core/detail/config.hpp>
+#include <boost/version.hpp>
+
+#if defined(BOOST_BEAST_USE_STD_STRING_VIEW)
+#include <string_view>
+#else
+#include <boost/utility/string_view.hpp>
+#endif
+
+#include <algorithm>
+
+namespace boost {
+namespace beast {
+
+#if defined(BOOST_BEAST_USE_STD_STRING_VIEW)
+  /// The type of string view used by the library
+  using string_view = std::string_view;
+
+  /// The type of basic string view used by the library
+  template<class CharT, class Traits>
+  using basic_string_view =
+      std::basic_string_view<CharT, Traits>;
+#else
+  /// The type of string view used by the library
+  using string_view = boost::string_view;
+
+  /// The type of basic string view used by the library
+  template<class CharT, class Traits>
+  using basic_string_view =
+      boost::basic_string_view<CharT, Traits>;
+#endif
+
+namespace detail {
+
+inline
+char
+ascii_tolower(char c)
+{
+    return ((static_cast<unsigned>(c) - 65U) < 26) ?
+        c + 'a' - 'A' : c;
+}
+
+template<class = void>
+bool
+iequals(
+    beast::string_view lhs,
+    beast::string_view rhs)
+{
+    auto n = lhs.size();
+    if(rhs.size() != n)
+        return false;
+    auto p1 = lhs.data();
+    auto p2 = rhs.data();
+    char a, b;
+    // fast loop
+    while(n--)
+    {
+        a = *p1++;
+        b = *p2++;
+        if(a != b)
+            goto slow;
+    }
+    return true;
+slow:
+    do
+    {
+        if(ascii_tolower(a) != ascii_tolower(b))
+            return false;
+        a = *p1++;
+        b = *p2++;
+    }
+    while(n--);
+    return true;
+}
+
+} // detail
+
+/** Returns `true` if two strings are equal, using a case-insensitive comparison.
+
+    The case-comparison operation is defined only for low-ASCII characters.
+
+    @param lhs The string on the left side of the equality
+
+    @param rhs The string on the right side of the equality
+*/
+inline
+bool
+iequals(
+    beast::string_view lhs,
+    beast::string_view rhs)
+{
+    return detail::iequals(lhs, rhs);
+}
+
+/** A case-insensitive less predicate for strings.
+
+    The case-comparison operation is defined only for low-ASCII characters.
+*/
+struct iless
+{
+    bool
+    operator()(
+        string_view lhs,
+        string_view rhs) const
+    {
+        using std::begin;
+        using std::end;
+        return std::lexicographical_compare(
+            begin(lhs), end(lhs), begin(rhs), end(rhs),
+            [](char c1, char c2)
+            {
+                return detail::ascii_tolower(c1) < detail::ascii_tolower(c2);
+            }
+        );
+    }
+};
+
+/** A case-insensitive equality predicate for strings.
+
+    The case-comparison operation is defined only for low-ASCII characters.
+*/
+struct iequal
+{
+    bool
+    operator()(
+        string_view lhs,
+        string_view rhs) const
+    {
+        return iequals(lhs, rhs);
+    }
+};
+
+} // beast
+} // boost
+
+#endif