id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9335	default constructed split_iterator has UB when copy constructed	nlewycky@…	Marshall Clow	"The copy constructor for split_iterator is:
{{{
            split_iterator( const split_iterator& Other ) :
                base_type(Other),
                m_Match(Other.m_Match),
                m_Next(Other.m_Next),
                m_End(Other.m_End),
                m_bEof(Other.m_bEof)
            {}
}}}
Note that the member copies in the constructor initializer list perform lvalue-to-rvalue conversion. That has undefined behaviour when the value is uninitialized.

The default constructor is implemented as so:
{{{
            split_iterator() {}
}}}

This means that if you default-construct a split_iterator then try to copy it, the copy ctor will exhibit undefined behaviour. I think this was intended to be valid, all default-constructed split_iterators compare equal.

The two possible fixes are to either change the default constructor to initialize the four members, or to change the copy constructor to use memcpy to copy the value representation instead of the object representation (I haven't checked whether all the members are trivially copyable)."	Bugs	closed	To Be Determined	string_algo	Boost Development Trunk	Problem	fixed	split_iterator	gromer@…