Le 31/03/12 08:49, Vicente J. Botet Escriba a écrit :

Hi,

Given the following explicit bool conversion

template<typename Mutex> class unique_lock { public: explicit operator bool() const BOOST_NOEXCEPT

I was expecting the following code to compile fail (note the int cast)

boost::unique_lock<boost::mutex> lk0; int i = int(lk0);

It fails with gcc-4.7.0, but compile with gcc-4.6.2 and clang-3.0 (I have not tested yet with msvc).

When BOOST_NO_EXPLICIT_CONVERSION_OPERATORS is defined I use the bool safe idiom to emulate the conversion

#if defined(BOOST_NO_EXPLICIT_CONVERSION_OPERATORS) typedef void (unique_lock::*bool_type)(); operator bool_type() const BOOST_NOEXCEPT; bool operator!() const BOOST_NOEXCEPT; #else explicit operator bool() const BOOST_NOEXCEPT; #endif

and in this case the compile fail as desired.

Do we need a new macro to state that even if explicit operators are provide, there are some unexpected conversions that could be introduced?

Hi, has anyone some comments on this issue? Best, Vicente