My implementation seems to be running almost as fast as raw pointers, which I think is a good sign. What worries me here is why Boost is running slower. Have I missed something in my implementation that is important and I might get into trouble for later? So the idea behind this is ma...
Indirection through an invalid pointer value and passing an invalid pointer value to a deallocation function have undefined behavior. Any other use of an invalid pointer value has implementation-defined behavior. Pointers to objects A pointer to object can be initialized with the return value of the...
class Misc { public: void sendData(std::map<std::string, std::string> data) { // function implementation } }; 如果尝试在另一个地方(例如线程初始化)使用这个函数指针,错误的用法可能如下所示: cpp Misc miscObj; std::thread t1(&Misc::sendData, miscObj, toSend); // 假设 to...
In the sense that pointers are necessary for the implementation of linked data structures, Java does have pointers; they are simply not presented as such to the programmer. The question is whether an entity can be called a pointer when its referent cannot be independently exposed in the language...
A null pointer should not be confused with an uninitialized pointer: a null pointeris guaranteed to compare unequal to any pointer that points to a valid object. However, depending on the language and implementation, an uninitialized pointer may not have any such guarantee. ...
I have a problem where I want to copy a std::function<> object around. The implementation of the actual std::function class is rather complicated -- it involves templates and virtual functions. Let me just get rid of this and copy a pointer to a heap generated pointer to the std::func...
Loose the cast, you don't need it in C and it is one more thing to get wrong. int **p = calloc(2, sizeof(int *)); Also, why bother to worry about the type when you can let the compiler do it, it's another thing to get wrong. ...
How the compiler rewrites functions is an implementation-specific detail, but the end-result is something like this: static void setID(Simple* const this, int id) { this->m_id = id; } Copy Note that our setId function has a new leftmost parameter named this, which is a const pointer...
Also important to consider is that in C++ virtual functions can be overwritten by derived classed. In this examplePtmfXoverwrites the virtual functionPtmfC::learnC2with its own implementationPtmfX:learnC2. Direct member function invocation
上面的代码将之前头文件中的所有细节隐藏到SomeClassPrivate之中,用户对于SomeClassPrivate可以是一无所知的,无论怎么修改SomeClassPrivate的内存布局,都不会影响用户对SomeClass的使用,也不会存在兼容性问题。另外由于没有引入额外头文件,不会发生宏展开,对A、B和C头文件的修改只会让someclass.cpp重新编译,并不会影...