[boost] Variadic append for std::string

Hi, One frequently needs to append stuff to strings, but the standard way (s += "A" + "B" + to_string(42)) isn't optimal due to temporaries. A variadic append() for std::string seems like the obvious solution. It could support string_view (boost and std), integers, maybe floats but without formatting options.. It could even be extensible by calling append(s, t); append(s, "A", "B", 42); Would this be useful for the Boost String Algo lib? -- Olaf