feat add StrJoin

src/strings/utils.cc

@@ -0,0 +1,23 @@
+#include "sled/strings/utils.h"
+#include <sstream>
+
+namespace sled {
+
+std::string
+StrJoin(const std::vector<std::string> &strings,
+        const std::string &delim,
+        bool skip_empty)
+{
+    if (strings.empty()) { return ""; }
+
+    std::stringstream ss;
+    size_t i = 0;
+    while (skip_empty && i < strings.size() && strings[i].empty()) { ++i; }
+    if (i < strings.size()) { ss << strings[i++]; }
+    for (; i < strings.size(); ++i) {
+        if (skip_empty && strings[i].empty()) { continue; }
+        ss << delim << strings[i];
+    }
+    return ss.str();
+}
+}// namespace sled