Boost C++ Libraries: Ticket #10493: Since 1.56, any_range with non-reference references can cause UB

cc set

Fri, 19 Dec 2014 14:36:51 GMT

cc p.omta@… added

status, milestone changed

Neil Groves — Mon, 02 Feb 2015 01:15:56 GMT

status new → assigned
milestone To Be Determined → Boost 1.58.0

anonymous — Mon, 27 Apr 2015 12:50:24 GMT

Just reproduced it with boost 1.58 after migration from 1.55. I tried to play with it and found how to make it work.

Using const std::string instead of std::string, seems fix the problem

typedef boost::any_range<
    std::string,
    boost::forward_traversal_tag,
    const std::string,
    std::ptrdiff_t
> range_t;

I haven't digged into any_iterator sources but seems it behave differently when Reference is const

kozlov.taras@… — Mon, 27 Apr 2015 12:58:58 GMT

Forget to add email in previous comment

Mon, 07 Sep 2015 13:05:11 GMT

Still present in 1.59.0

The problem is becoming more visible with MSVC++2015 because the compiler is better in detecting dangling references and emitting errors for them. To hard code those checks, just add the following assert into every dereference() method in range/detail/any_iterator_wrapper.hpp:

static_assert(
   !std::is_lvalue_reference<reference>::value
   || std::is_lvalue_reference<decltype(*m_it)>::value,
   "dangling ref"
);

A little bit of digging in the headers shows that the problem lies in range/detail/any_iterator_interface.hpp, where any_incrementable_iterator_interface's

typedef Reference reference;

was changed in 1.56.0 to

typedef typename mutable_reference_type_generator<
    Reference
>::type reference;

Rolling this back solves the problem for our codebase. Any possibilities of having this fixed soon?

version, milestone changed

wslcdg@… — Tue, 07 Feb 2017 14:21:53 GMT

version Boost 1.56.0 → Boost 1.62.0
milestone Boost 1.58.0 → Boost 1.64.0

Problem still exists boost 1.62

o.andriyanov@… — Fri, 06 Oct 2017 15:17:30 GMT

Still have this bug in 1.64. Adding const to Reference works around the problem but disables move construction. Is there any other workaround?

jeremy.coulon.jrmc@… — Thu, 08 Mar 2018 08:44:24 GMT

Problem still there in boost 1.65.1

Adding const to Reference doesn't workaround the problem (at least on Visual Studio): c:\path\to\boost\1.65.1\include\boost\range\detail\any_iterator_wrapper.hpp(302) : warning C4172: returning address of local variable or temporary