refactor(string_util): Use rvalue references for *trim()

include/utils/string.hpp

@@ -23,9 +23,9 @@ namespace string_util {
   string squeeze(const string& haystack, char needle);
   string strip(const string& haystack, char needle);
   string strip_trailing_newline(const string& haystack);
-  string ltrim(const string& haystack, char needle);
+  string ltrim(string&& value, const char& needle);
-  string rtrim(const string& haystack, char needle);
+  string rtrim(string&& value, const char& needle);
-  string trim(const string& haystack, char needle);
+  string trim(string&& value, const char& needle);
   string join(const vector<string>& strs, const string& delim);
   vector<string>& split_into(const string& s, char delim, vector<string>& container);
   vector<string> split(const string& s, char delim);

src/components/config.cpp

@@ -95,6 +95,8 @@ void config::parse_file() {
     if (line[0] == '[' && line[line.length() - 1] == ']') {
       section = line.substr(1, line.length() - 2);
       continue;
+    } else if (section.empty()) {
+      continue;
     }
 
     size_t equal_pos;
@@ -104,14 +106,19 @@ void config::parse_file() {
       continue;
     }
 
-    string key{string_util::trim(line.substr(0, equal_pos), ' ')};
+    string key{forward<string>(string_util::trim(forward<string>(line.substr(0, equal_pos)), ' '))};
-    string value{string_util::trim(string_util::trim(line.substr(equal_pos + 1), ' '), '"')};
 
     auto it = m_sections[section].find(key);
     if (it != m_sections[section].end()) {
       throw key_error("Duplicate key name \"" + key + "\" defined on line " + to_string(lineno));
     }
 
+    if (line.size() > equal_pos + 1) {
+      line.erase(0, equal_pos + 1);
+    }
+
+    string value{string_util::trim(string_util::trim(move(line), ' '), '"')};
+
     m_sections[section].emplace_hint(it, move(key), move(value));
   }
 

src/components/parser.cpp

@@ -46,7 +46,7 @@ void parser::codeblock(string&& data) {
   size_t pos;
 
   while (data.length()) {
-    data = string_util::ltrim(data, ' ');
+    data = string_util::ltrim(move(data), ' ');
 
     if (data.empty()) {
       break;

src/drawtypes/animation.cpp

@@ -45,7 +45,7 @@ namespace drawtypes {
     vector<icon_t> vec;
     vector<string> frames;
 
-    name = string_util::ltrim(string_util::rtrim(name, '>'), '<');
+    name = string_util::ltrim(string_util::rtrim(move(name), '>'), '<');
 
     auto anim_defaults = load_optional_icon(conf, section, name);
 

src/drawtypes/label.cpp

@@ -124,7 +124,7 @@ namespace drawtypes {
     vector<token> tokens;
     size_t start, end, pos;
 
-    name = string_util::ltrim(string_util::rtrim(name, '>'), '<');
+    name = string_util::ltrim(string_util::rtrim(move(name), '>'), '<');
 
     string text;
 

src/drawtypes/progressbar.cpp

@@ -87,7 +87,7 @@ namespace drawtypes {
    */
   progressbar_t load_progressbar(const bar_settings& bar, const config& conf, const string& section, string name) {
     // Remove the start and end tag from the name in case a format tag is passed
-    name = string_util::ltrim(string_util::rtrim(name, '>'), '<');
+    name = string_util::ltrim(string_util::rtrim(move(name), '>'), '<');
 
     string format = "%fill%%indicator%%empty%";
     unsigned int width;

src/drawtypes/ramp.cpp

@@ -27,7 +27,7 @@ namespace drawtypes {
    * from the configuration
    */
   ramp_t load_ramp(const config& conf, const string& section, string name, bool required) {
-    name = string_util::ltrim(string_util::rtrim(name, '>'), '<');
+    name = string_util::ltrim(string_util::rtrim(move(name), '>'), '<');
 
     auto ramp_defaults = load_optional_icon(conf, section, name);
 

src/modules/i3.cpp

@@ -142,7 +142,7 @@ namespace modules {
         }
 
         // Trim leading and trailing whitespace
-        ws_name = string_util::trim(ws_name, ' ');
+        ws_name = string_util::trim(move(ws_name), ' ');
 
         auto icon = m_icons->get(ws->name, DEFAULT_WS_ICON);
         auto label = m_statelabels.find(ws_state)->second->clone();

src/utils/string.cpp

@@ -122,7 +122,7 @@ namespace string_util {
   /**
    * Remove needle from the start of the string
    */
-  string ltrim(const string& haystack, char needle) {
+  string ltrim(string&& haystack, const char& needle) {
     string str(haystack);
     while (str[0] == needle) {
       str.erase(0, 1);
@@ -133,7 +133,7 @@ namespace string_util {
   /**
    * Remove needle from the end of the string
    */
-  string rtrim(const string& haystack, char needle) {
+  string rtrim(string&& haystack, const char& needle) {
     string str(haystack);
     while (str[str.length() - 1] == needle) {
       str.erase(str.length() - 1, 1);
@@ -144,8 +144,8 @@ namespace string_util {
   /**
    * Remove needle from the start and end of the string
    */
-  string trim(const string& haystack, char needle) {
+  string trim(string&& value, const char& needle) {
-    return rtrim(ltrim(haystack, needle), needle);
+    return rtrim(ltrim(move(value), needle), needle);
   }
 
   /**