replaced old trim function based on std::string by one using string_view

Author: gittiver

include/crow/middlewares/cookie_parser.h

@@ -243,15 +243,6 @@ namespace crow
 
             const std::string_view cookies_sv = req.get_header_value("Cookie");
 
-            auto trim_sv = [](const std::string_view sv) -> std::string_view {
-                const size_t first = sv.find_first_not_of(" \t\n\r\f\v"); // same as isspace
-                if (std::string_view::npos == first) {
-                    return sv.substr(0, 0);
-                }
-                const size_t last = sv.find_last_not_of(" \t\n\r\f\v");
-                return sv.substr(first, (last - first + 1));
-            };
-
             size_t pos = 0;
             while (pos < cookies_sv.size())
             {
@@ -261,7 +252,7 @@ namespace crow
                 }
 
                 std::string_view name_sv = cookies_sv.substr(pos, pos_equal - pos);
-                name_sv = trim_sv(name_sv);
+                name_sv = utility::trim(name_sv);
 
                 pos = pos_equal + 1;
                 if (pos == cookies_sv.size()) {
@@ -279,7 +270,7 @@ namespace crow
                      pos = pos_semicolon + 1;
                 }
 
-                value_sv = trim_sv(value_sv);
+                value_sv = utility::trim(value_sv);
 
                 if (!value_sv.empty() && value_sv.front() == '"' && value_sv.back() == '"')
                 {

include/crow/utility.h

@@ -855,41 +855,18 @@ namespace crow
             return res;
         }
 
-
-        /// Return a copy of the given string with its
+        /// Return string view of the given string view with its
         /// leading and trailing whitespaces removed.
-        inline static std::string trim(const std::string& v)
-        {
-            if (v.empty())
-                return "";
-
-            size_t begin = 0, end = v.length();
-
-            size_t i;
-            for (i = 0; i < v.length(); i++)
-            {
-                if (!std::isspace(v[i]))
-                {
-                    begin = i;
-                    break;
-                }
+        inline static std::string_view trim(const std::string_view sv) {
+            const size_t first = sv.find_first_not_of(" \t\n\r\f\v"); // same as isspace
+            if (std::string_view::npos == first) {
+                return sv.substr(0, 0);
             }
-
-            if (i == v.length())
-                return "";
-
-            for (i = v.length(); i > 0; i--)
-            {
-                if (!std::isspace(v[i - 1]))
-                {
-                    end = i;
-                    break;
-                }
-            }
-
-            return v.substr(begin, end - begin);
+            const size_t last = sv.find_last_not_of(" \t\n\r\f\v");
+            return sv.substr(first, (last - first + 1));
         }
 
+
         /**
          * @brief splits a string based on a separator
          */