Squashed 'external/mio/' content from commit 8b6b7d8

git-subtree-dir: external/mio
git-subtree-split: 8b6b7d878c89e81614d05edca7936de41ccdd2da

include/mio/detail/string_util.hpp

@@ -0,0 +1,170 @@
+/* Copyright 2017 https://github.com/mandreyel
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this
+ * software and associated documentation files (the "Software"), to deal in the Software
+ * without restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies
+ * or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef MIO_STRING_UTIL_HEADER
+#define MIO_STRING_UTIL_HEADER
+
+#include <type_traits>
+
+namespace mio {
+namespace detail {
+
+template<
+    typename S,
+    typename C = typename std::decay<S>::type,
+    typename = decltype(std::declval<C>().data()),
+    typename = typename std::enable_if<
+        std::is_same<typename C::value_type, char>::value
+#ifdef _WIN32
+        || std::is_same<typename C::value_type, wchar_t>::value
+#endif
+    >::type
+> struct char_type_helper {
+    using type = typename C::value_type;
+};
+
+template<class T>
+struct char_type {
+    using type = typename char_type_helper<T>::type;
+};
+
+// TODO: can we avoid this brute force approach?
+template<>
+struct char_type<char*> {
+    using type = char;
+};
+
+template<>
+struct char_type<const char*> {
+    using type = char;
+};
+
+template<size_t N>
+struct char_type<char[N]> {
+    using type = char;
+};
+
+template<size_t N>
+struct char_type<const char[N]> {
+    using type = char;
+};
+
+#ifdef _WIN32
+template<>
+struct char_type<wchar_t*> {
+    using type = wchar_t;
+};
+
+template<>
+struct char_type<const wchar_t*> {
+    using type = wchar_t;
+};
+
+template<size_t N>
+struct char_type<wchar_t[N]> {
+    using type = wchar_t;
+};
+
+template<size_t N>
+struct char_type<const wchar_t[N]> {
+    using type = wchar_t;
+};
+#endif // _WIN32
+
+template<typename CharT, typename S>
+struct is_c_str_helper
+{
+    static constexpr bool value = std::is_same<
+        CharT*,
+        // TODO: I'm so sorry for this... Can this be made cleaner?
+        typename std::add_pointer<
+            typename std::remove_cv<
+                typename std::remove_pointer<
+                    typename std::decay<
+                        S
+                    >::type
+                >::type
+            >::type
+        >::type
+    >::value;
+};
+
+template<typename S>
+struct is_c_str
+{
+    static constexpr bool value = is_c_str_helper<char, S>::value;
+};
+
+#ifdef _WIN32
+template<typename S>
+struct is_c_wstr
+{
+    static constexpr bool value = is_c_str_helper<wchar_t, S>::value;
+};
+#endif // _WIN32
+
+template<typename S>
+struct is_c_str_or_c_wstr
+{
+    static constexpr bool value = is_c_str<S>::value
+#ifdef _WIN32
+        || is_c_wstr<S>::value
+#endif
+        ;
+};
+
+template<
+    typename String,
+    typename = decltype(std::declval<String>().data()),
+    typename = typename std::enable_if<!is_c_str_or_c_wstr<String>::value>::type
+> const typename char_type<String>::type* c_str(const String& path)
+{
+    return path.data();
+}
+
+template<
+    typename String,
+    typename = decltype(std::declval<String>().empty()),
+    typename = typename std::enable_if<!is_c_str_or_c_wstr<String>::value>::type
+> bool empty(const String& path)
+{
+    return path.empty();
+}
+
+template<
+    typename String,
+    typename = typename std::enable_if<is_c_str_or_c_wstr<String>::value>::type
+> const typename char_type<String>::type* c_str(String path)
+{
+    return path;
+}
+
+template<
+    typename String,
+    typename = typename std::enable_if<is_c_str_or_c_wstr<String>::value>::type
+> bool empty(String path)
+{
+    return !path || (*path == 0);
+}
+
+} // namespace detail
+} // namespace mio
+
+#endif // MIO_STRING_UTIL_HEADER