CppCoreGuidelines R.10 避免使用 malloc() 和 free()

class Record {
    int id;
    string name;
    // ...
};

void use()
{
    // p1 might be nullptr
    // *p1 is not initialized; in particular,
    // that string isn't a string, but a string-sized bag of bits
    Record* p1 = static_cast<Record*>(malloc(sizeof(Record)));

    auto p2 = new Record;

    // unless an exception is thrown, *p2 is default initialized
    auto p3 = new(nothrow) Record;
    // p3 might be nullptr; if not, *p3 is default initialized

    // ...

    delete p1;    // error: cannot delete object allocated by malloc()
    free(p2);    // error: cannot free() object allocated by new
}