{ return hppbard{}; }

Variadic templates appeared in C++11 to cover such cases when you would have a template functions that could have a numerous members of different types. Doesn't it remind you of variadic functions that uses va_start, va_arg, va_end and so others? Cause it should be.

In some languages there is such a thing as tuple which makes real to write such code (this time it's in python): def f(x):  #   do stuff return (True, modified_string) success, modified_string = f(something)  C++ hadn't such feature until C++11. That was one of the reasons to pass variable as referenced argument, which ended up creating huge code bases that have unused arguments in it's functions. That happened in order to save revers compatibility and allow clients to use stable interfaces to access libraries without checking the version of dynamically attached library in order to use correct functions.