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void f(const std::string& s) { cout << s << endl };

void g() {
  for (int i = 0; i <  1000; ++i) { f("hello"); };
}

Wiki MarkupThis actually allocates, copies and deletes 1000 heap buffers with the string "hello"! The problem here is that "hello" is _not_ an instance of {{std::string}}. It is a char\[5\] that must be converted to a temporary {{std::string}} using the appropriate constructor. However {{std::string}} always wants to manage its own memory, so the constructor allocates a new buffer and copies the string. Once f() returns and we go round the loop again the temporary is deleted along with its buffer.

Here's a better solution:

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