Boost C++ Libraries: Ticket #12577: Null reference in pair.hpp triggers runtime warning with -fsanitize=undefined

status changed; resolution set

Ion Gaztañaga — Sat, 12 Nov 2016 23:20:40 GMT

status new → closed
resolution → fixed

Thanks for the report.

The null value is never used, but sanitizers should work. A workaround was pushed and I confirmed it with GCC 6.2 and -fsanitize=address:

https://github.com/boostorg/container/commit/77f5d7218da42db37b4fecc97f7c389a9e6b9cd4

Eric Niebler — Tue, 24 Jan 2017 01:56:31 GMT

This code requires global constructors, which causes a warning on some compilers. Why isn't this simply:

template <class T>
struct static_constexpr {
    static constexpr T const value {};
};
template <class T>
constexpr T const static_constexpr<T>::value;
using piecewise_construct_t = std::piecewise_construct_t const &;
namespace {
  piecewise_construct_t piecewise_construct =
    static_constexpr<std::piecewise_construct_t>::value;
}