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c++c++11vectorshared-ptrassert

c++ how to assert that all std::shared_ptr in a vector are referring to something

When I have a function receiving a (smart) pointer that is supposed to refer something, I always start as follows:

class Foo;
void doSomething(const std::shared_ptr<Foo>& pFoo)
{
    assert(pFoo);
    // ...
}

Now I am looking for a similar assert condition for a vector (or other container) of (smart) pointers. The best I could come up with is:

void doSomething(const std::vector<std::shared_ptr<Foo> >& pFoos)
{
    assert(std::all_of(pFoos.begin(), pFoos.end(), [](const std::shared_ptr<Foo>& pFoo) { return pFoo; }));
    // ...
}

I wonder whether this could be improved.. can the lambda be avoided? (I tried to use the get() method of shared_ptr but template deduction fails then) Or is there another way to assert for a whole container?

Solution

  • one more way to do it:

    assert(std::find(pFoos.begin(), pFoos.end(), nullptr) == pFoos.end());