Added thirdparty: boost library

thirdparty/include/boost/locale/util/string.hpp

@@ -0,0 +1,46 @@
+//
+// Copyright (c) 2022-2023 Alexander Grund
+//
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#ifndef BOOST_LOCALE_UTIL_STRING_HPP
+#define BOOST_LOCALE_UTIL_STRING_HPP
+
+#include <boost/locale/config.hpp>
+#include <limits>
+
+namespace boost { namespace locale { namespace util {
+    /// Return the end of a C-string, i.e. the pointer to the trailing NULL byte
+    template<typename Char>
+    Char* str_end(Char* str)
+    {
+        while(*str)
+            ++str;
+        return str;
+    }
+
+    inline constexpr bool is_upper_ascii(const char c)
+    {
+        return 'A' <= c && c <= 'Z';
+    }
+
+    inline constexpr bool is_lower_ascii(const char c)
+    {
+        return 'a' <= c && c <= 'z';
+    }
+
+    inline constexpr bool is_numeric_ascii(const char c)
+    {
+        return '0' <= c && c <= '9';
+    }
+
+    /// Cast an unsigned char to a (possibly signed) char avoiding implementation defined behavior
+    constexpr char to_char(unsigned char c)
+    {
+        return static_cast<char>((c - (std::numeric_limits<char>::min)()) + (std::numeric_limits<char>::min)());
+    }
+
+}}} // namespace boost::locale::util
+
+#endif