add within

tests/string.cpp

@@ -0,0 +1,13 @@
+#include <gtest/gtest.h>
+#include <string>
+#include <vector>
+
+#include "string/string.hpp"
+
+
+TEST(split_str, check)
+{
+  hack::v_str v { "asdf", "qwer", "zxcv" };
+
+  ASSERT_EQ(hack::split_str("asdf,qwer,zxcv", ','), v);
+}