[function] Comparison with nullptr differs from std::function<>

[boost@…]

Whether or not boost::function<> should support comparison with (C++11) nullptr is another issue, but at the moment it is inconsistent with std::function<>.

E.g.

boost::function<void ()> bf;
bool c1 = (bf == nullptr);   // currently false

std::function<void ()> sf;
bool c2 = (sf == nullptr);   // true

assert(c1 == c2);

Tested with g++ 4.6.3 and Visual Studio 2012.

[anonymous]

I add a major hit count for this to be fixed!

[Ryan.Livingston@…]

Just encountered this in our code base. We ran clang-tidy with modernize-use-nullptr which converted some code from:

if (aBoostFunction == NULL) {
    ...
} else {
    aBoostFunction(...);
}

to:

if (aBoostFunction == nullptr) {
    ...
} else {
    aBoostFunction(...);
}

This change caused the comparison to return false as shown above and the empty function was invoked.