Update create_dir

include/spdlog/details/os-inl.h

@@ -485,27 +485,30 @@ SPDLOG_INLINE bool create_dir(filename_t path)
     {
         return true;
     }
-    using char_type = filename_t::value_type;
-    std::basic_istringstream<char_type> istream(path);
-    filename_t token;
-    filename_t cur_dir;    
-
+        
 #ifdef _WIN32
     // support forward slash in windows
 	std::replace(path.begin(), path.end(), '/', folder_sep);
-#endif
-    while (std::getline(istream, token, folder_sep))
-    {
-        if (!token.empty())
-        {
-            cur_dir += token;
-            if (!file_exists(cur_dir) && !mkdir_(cur_dir))
-            {
-                return false;
-            }
-        }
-        cur_dir += folder_sep;
-    }
+#endif	
+
+	size_t search_offset = 0;
+	do
+	{		
+		auto token_pos = path.find(folder_sep, search_offset);
+		// treat the entire path as a folder if no folder separator not found
+		if (token_pos == filename_t::npos)
+		{
+			token_pos = path.size();
+		}
+
+		auto subdir = path.substr(0, token_pos);
+
+		if (!subdir.empty() && !file_exists(subdir) && !mkdir_(subdir))
+		{
+			return false; // return error if failed creating dir
+		}
+		search_offset = token_pos + 1;
+	} while (search_offset < path.size());
 
     return true;
 }
@@ -517,10 +520,6 @@ SPDLOG_INLINE bool create_dir(filename_t path)
 // "abc///" => "abc//"
 SPDLOG_INLINE filename_t dir_name(filename_t path)
 {    
-#ifdef _WIN32
-    // support forward slash in windows
-	std::replace(path.begin(), path.end(), '/', folder_sep);
-#endif
     auto pos = path.find_last_of(folder_sep);
     return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
 }