小编use*_*912的帖子

我惊讶地发现这段代码编译:

#include <functional>

struct Callable {
    void operator() () { count++; }
    void operator() () const = delete;
    int count = 0;
};

int main() {
    const Callable counter;
    // counter(); //error: use of deleted function 'void Callable::operator()() const'
    std::function<void(void)> f = counter;
    f();

    const auto cf = f;
    cf();

}

https://wandbox.org/permlink/FH3PoiYewklxmiXl

这将调用非const调用运算符Callable.相比之下,如果你这样做,const auto cf = counter; cf();它会按预期出错.那么,为什么const正确性似乎没有被遵循std::function？