Use move semantics in trim and history_item_t

src/history.cpp

@@ -171,10 +171,8 @@ bool history_item_t::merge(const history_item_t &item) {
     return result;
 }
 
-history_item_t::history_item_t(const wcstring &str, time_t when, history_identifier_t ident)
-    : creation_timestamp(when), identifier(ident) {
-    contents = trim(str);
-}
+history_item_t::history_item_t(wcstring str, time_t when, history_identifier_t ident)
+    : contents(trim(std::move(str))), creation_timestamp(when), identifier(ident) {}
 
 bool history_item_t::matches_search(const wcstring &term, enum history_search_type_t type,
                                     bool case_sensitive) const {

src/history.h

@@ -82,7 +82,7 @@ class history_item_t {
     path_list_t required_paths;
 
    public:
-    explicit history_item_t(const wcstring &str = wcstring(), time_t when = 0,
+    explicit history_item_t(wcstring str = wcstring(), time_t when = 0,
                             history_identifier_t ident = 0);
 
     const wcstring &str() const { return contents; }

src/wcstringutil.cpp

@@ -49,16 +49,19 @@ wcstring truncate(const wcstring &input, int max_len, ellipsis_type etype) {
     return output;
 }
 
-wcstring trim(const wcstring &input) { return trim(input, L"\t\v \r\n"); }
+wcstring trim(wcstring input) { return trim(std::move(input), L"\t\v \r\n"); }
 
-wcstring trim(const wcstring &input, const wchar_t *any_of) {
-    auto begin_offset = input.find_first_not_of(any_of);
-    if (begin_offset == wcstring::npos) {
+wcstring trim(wcstring input, const wchar_t *any_of) {
+    wcstring result = std::move(input);
+    size_t suffix = result.find_last_not_of(any_of);
+    if (suffix == wcstring::npos) {
         return wcstring{};
     }
-    auto end = input.cbegin() + input.find_last_not_of(any_of);
+    result.erase(suffix + 1);
 
-    wcstring result(input.begin() + begin_offset, end + 1);
+    auto prefix = result.find_first_not_of(any_of);
+    assert(prefix != wcstring::npos && "Should have one non-trimmed character");
+    result.erase(0, prefix);
     return result;
 }
 

src/wcstringutil.h

@@ -65,8 +65,8 @@ enum class ellipsis_type {
 
 wcstring truncate(const wcstring &input, int max_len,
                   ellipsis_type etype = ellipsis_type::Prettiest);
-wcstring trim(const wcstring &input);
-wcstring trim(const wcstring &input, const wchar_t *any_of);
+wcstring trim(wcstring input);
+wcstring trim(wcstring input, const wchar_t *any_of);
 
 /// Converts a string to lowercase.
 wcstring wcstolower(wcstring input);