In short; undefined is where no notion of the thing exists; it has no type, and it's never been referenced before in that scope; null is where the thing is known to exist, but it's not known what the value is. One thing to remember is that null is not, conceptually, the same a...
>>Compile error identifier "clock_t" is undefined This sounds weird to me. Please provide more information about your project. What's the type of your project? It will be better if you could provide a demo project for us to test so that we could help you find the root cause....
However, it is for this very reason that it promotes a coding pattern that is "utterly broken" (to use Douglas Cockcroft's words). To explain, it is very common practice to test for null and undefined in shorthand, furthermore this test is one of the most common tests in most code ba...
error C2665: 'CObject::operator new' : none of the 3 overloads could convert all the argument types_, but it is a constructor with no arguements error C2678: '==' binary: no operator found which takes a left operand of type 'CSchemaString' (or there is no acceptable conversion) er...