id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
12194	Copy assignment on moveable and copyable classes uses wrong type	a.grund@…	Ion Gaztañaga	"A patch introduced a breaking change to classes that are copyable and movable: https://github.com/boostorg/move/commit/4f9c2b62fbdcf5995ecf50a2ecf2494048a6696d#diff-6a11d48d06dd33c1193ffb3d794787fbR252

The macro was changed so the {{{TYPE& operator=(TYPE &t)}}} calls the assignement operator with a type {{{ const TYPE& }}} instead of {{{ const ::boost::rv<TYPE> & }}}

This change is not described and seems to be a mistake that was not caught in the review process. As the macro {{{ BOOST_COPY_ASSIGN_REF }}} still expands to the original rv-type a wrong operator might get called. A minimum example:


{{{
#include <boost/move/move.hpp>
#include <cassert>

class Foo{
    BOOST_COPYABLE_AND_MOVABLE(Foo)
public:
    int i;
    explicit Foo(int val): i(val){}
    Foo(BOOST_RV_REF(Foo) obj): i(obj.i) {}
    Foo& operator=(BOOST_RV_REF(Foo) rhs){ i = rhs.i; return *this; }
    Foo& operator=(BOOST_COPY_ASSIGN_REF(Foo) rhs){ i = rhs.i; return *this; }
    template<class OTHER>
    Foo& operator=(const OTHER& rhs){ i = rhs.j; return *this; }
};

struct Bar{
    int j;
    explicit Bar(int val): j(val){}
};

int main(){
    Foo foo1(1);
    Foo foo2(2);
    Bar bar(3);
    assert(foo1.i == 1);
    assert(foo2.i == 2);
    assert(bar.j == 3);
    foo2 = foo1;
    assert(foo1.i == 1);
    assert(foo2.i == 1);
    foo1 = bar;
    assert(foo1.i == 3);
    return 0;
}
}}}

This compiles and works fine in boost <=1.58 but fails in >=1.59 as the template version is called."	Bugs	closed	Boost 1.61.0	move	Boost 1.59.0	Regression	fixed