+ // ensure we have at least one character
+ if (str.empty() == true)
+ return str;
+
+ char const * const s = str.c_str();
+ size_t start = 0;
+ for (; isspace(s[start]) != 0; ++start)
+ ; // find the first not-space
+
+ // string contains only whitespaces
+ if (s[start] == '\0')