danglingTemporaryLifetime false positive

[Cyphall]

It seems that saving the address of an element when iterating on a temporary std::span triggers this error.

Sample code:

#include <span>
#include <vector>

std::span<const int> getSpan(const std::vector<int>& vec)
{
    return vec;
}

int main()
{
    std::vector<int> values = {0, 1, 2, 3, 4};

    const int* selectedValue = nullptr;
    for (const int& value : getSpan(values))
    {
        if (value == 2)
        {
            selectedValue = &value;
            break;
        }
    }

    return selectedValue ? *selectedValue : 0;
}

Here, the std::span is temporary in the scope of the for loop, but not the objects it points to.

cppcheck error (file paths were removed):

error: Using pointer that is a temporary. [danglingTemporaryLifetime]
 return selectedValue ? *selectedValue : 0;
        ^
note: Assigned to reference.
 for (const int& value : getSpan(values))
                 ^
note: Address of variable taken here.
   selectedValue = &value;
                   ^
note: Temporary created here.
 for (const int& value : getSpan(values))
                                ^
note: Using pointer that is a temporary.
 return selectedValue ? *selectedValue : 0;
        ^

[CHR]

Thanks for reporting, ticket is here: https://trac.cppcheck.net/ticket/14014