Am Saturday 02 January 2010 16:42:45 schrieb vicente.botet:
I have looked at uninitialized_copy but if I have understood it correctly, it calls the copy constructor. I have tried with
class C { public: C* shallow_clone() { C* p = reinterpret_cast<C>(malloc(sizeof(C)); if (p==0) { throw std::bad_alloc(); } memcpy(p, this, sizeof(C)); return p; } };
But I suspect that this is not correct in general. Is this correct on some particular cases? if yes on witch ones? Is there a way to create such a cache instance without calling to the constructor in a portable way using some low level C++ interface?
new char[sizeof(T)], reinterpret_cast and std::memcpy(). the C++ standard explicitely requires char-arrays to be aligned appropriately for objects of any type that fits in the array. I don't know the requirements of your cache, but there are many cases were copying an object like this will fail. e.g. when the object contains a boost::interprocess::offset_ptr, so this is only a portable way to copy PODs.