`reset()` marked as deprecated

[Kojoley]

It should be a mistake that rest() of boost::optional is marked as deprecated because std::optional has reset() [optional.mod].

The story behind this finding

I am working on adding std::optional support for Spirit and it requires rewriting of optional handling. Currently it resets optional with boost::none and I wanted to generalize this (as I do not see a reason why it should handle boost and std optional differently) because I cannot reset std::optional with boost::none_t. The reset() method serves perfectly for this purpose, but the problem is that for some reason boost::optional has reset() marked as deprecated.

[akrzemi1]

Yes, I sympathize with the need. I cannot merge your PR as-is. Since deprecation a maintenance thereof has also been abandoned. It needs unit-testing, marking as noexcept, support in optional<T&>.

[Kojoley]

It needs unit-testing

optional/test/optional_test.cpp

Lines 148 to 160 in 106f9ae

	// Deinitialization of Initialized Optional
	// T::~T() is used to destroy previous value in ob.
	set_pending_dtor( ARG(T) ) ;
	ob.reset();
	check_is_not_pending_dtor( ARG(T) ) ;
	check_uninitialized(ob);
	// Deinitialization of Uninitialized Optional
	// (Dtor is not called this time)
	set_pending_dtor( ARG(T) ) ;
	ob.reset();
	check_is_pending_dtor( ARG(T) ) ;
	check_uninitialized(ob);

optional/test/optional_test.cpp

Lines 674 to 699 in 106f9ae

	//
	// Case 2: Only one Initialized.
	//
	reset_throw_on_assign( ARG(T) ) ;
	opt0.reset();
	opt1.reset(a);
	set_throw_on_copy( ARG(T) ) ;
	passed = false ;
	try
	{
	// This should attempt to swap optionals and fail at opt0.reset(*opt1)
	// Both opt0 and op1 are left unchanged (unswaped)
	swap(opt0,opt1);
	passed = true ;
	}
	catch ( ... ) {}
	BOOST_TEST(!passed);
	check_uninitialized(opt0);
	check_initialized(opt1);
	check_value(opt1,a,x);

marking as noexcept

optional/include/boost/optional/optional.hpp

Line 383 in 106f9ae

void reset() BOOST_NOEXCEPT { destroy(); }

optional/include/boost/optional/detail/optional_trivially_copyable_base.hpp

Line 132 in 106f9ae

void reset() BOOST_NOEXCEPT { destroy(); }

optional/include/boost/optional/detail/old_optional_implementation.hpp

Line 337 in 106f9ae

void reset() BOOST_NOEXCEPT { destroy(); }

optional/include/boost/optional/detail/optional_reference_spec.hpp

Line 159 in 106f9ae

void reset() BOOST_NOEXCEPT { ptr_ = 0; }

support in optional<T&>

optional/include/boost/optional/detail/optional_reference_spec.hpp

Line 159 in 106f9ae

void reset() BOOST_NOEXCEPT { ptr_ = 0; }

[akrzemi1]

Right. Sorry for too shallow an investigation on my side. I merged the PR with some minor modifications in the documentation.

[Kojoley]

Thanks!