This adds some additional checks the the C++98-style concept checks for
iterators, and removes some bogus checks for mutable iterators. Instead
of requiring that the result of dereferencing a mutable iterator is
assignable (which is a property of the value type, not required for the
iterator) check that the reference type is a non-const reference to the
value type.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
* include/bits/boost_concept_check.h (_ForwardIteratorConcept)
(_BidirectionalIteratorConcept, _RandomAccessIteratorConcept):
Check result types of iterator operations.
(_Mutable_ForwardIteratorConcept): Check that iterator's
reference type is a reference to its value type.
(_Mutable_BidirectionalIteratorConcept): Do not require the
value type to be assignable.
(_Mutable_RandomAccessIteratorConcept): Likewise.
* testsuite/24_iterators/operations/prev_neg.cc: Adjust dg-error
line number.