STL: structs shouldn't redundantly say public for their base classes

[StephanTLavavej]

struct access control defaults to public for both members and base classes: https://eel.is/c++draft/class.access.base#2

Several years ago, we started following a convention in the STL of not repeating public for structs, but there are at least 21 places that need to be updated. One example:

STL/stl/inc/utility

Lines 409 to 413 in 6b0238d

	template <size_t _Index, class _Tuple>
	struct tuple_element<_Index, const _Tuple> : public tuple_element<_Index, _Tuple> { // tuple_element for const
	using _Mybase = tuple_element<_Index, _Tuple>;
	using type = add_const_t<typename _Mybase::type>;
	};

The necessary change is simple:

-struct tuple_element<_Index, const _Tuple> : public tuple_element<_Index, _Tuple> { // tuple_element for const
+struct tuple_element<_Index, const _Tuple> : tuple_element<_Index, _Tuple> { // tuple_element for const

Find and fix as many as you can.

[lozinska]

Hello there! May I work on this issue?

[StephanTLavavej]

Yes, go for it! 😸

[lozinska]

Thank you