Implement N4089 Safe conversions in unique_ptr<T[]> (LWG 2118) and N4366 LWG 2228...

Implement N4089 Safe conversions in unique_ptr<T[]> (LWG 2118) and N4366 LWG 2228...

2015-08-08  Ville Voutilainen  <ville.voutilainen@gmail.com>

	Implement N4089 Safe conversions in unique_ptr<T[]> (LWG 2118)
	and N4366 LWG 2228: Missing SFINAE rule in unique_ptr
	templated assignment
	* include/bits/unique_ptr.h
	(__remove_cv, __is_derived_Tp): Remove.
	(default_delete::default_delete(const default_delete<_Up[]>)):
	Constrain with array convertibility.
	(default_delete::operator(_Up*)): Turn into a template,
	constrain with array convertibility.
	(__safe_conversion_up): New, single object version.
	(unique_ptr(unique_ptr<_Up, _Ep>&&)): Constrain with deleter
	convertibility.
	(unique_ptr::operator=(unique_ptr<_Up, _Ep>&&)): Likewise, and add
	is_assignable as a constraint.
	(__safe_conversion_up): Array version, renamed from __safe_conversion,
	updated to implement N4089.
	(__safe_conversion_raw): New.
	(unique_ptr(_Up)): Turn into a template, constrain with array
	convertibility.
	(unique_ptr(_Up,
        typename conditional<is_reference<deleter_type>::value,
        deleter_type, const deleter_type&>::type)): Likewise.
	(unique_ptr(_Up, typename
 	remove_reference<deleter_type>::type&&)): Likewise.
	(unique_ptr(unique_ptr<_Up, _Ep>&&)): Likewise.
	(operator=(unique_ptr<_Up, _Ep>&&)): Likewise, and add
	is_assignable as a constraint (array version).
	(reset(_Up)): Turn into a template, constrain with array
	convertibility.
	(reset(nullptr_t)): New.
	* testsuite/20_util/default_delete/48631_neg.cc: Adjust.
	* testsuite/20_util/unique_ptr/assign/48635.cc: Likewise.
	* testsuite/20_util/unique_ptr/assign/48635_neg.cc: Likewise.
	* testsuite/20_util/unique_ptr/assign/cv_qual.cc: Likewise.
	* testsuite/20_util/unique_ptr/cons/cv_qual.cc: Likewise.
	* testsuite/20_util/unique_ptr/dr2228.cc: New.
	* testsuite/20_util/unique_ptr/modifiers/cv_qual.cc: Adjust.

From-SVN: r226733