C++ Struct is compiled into class?
In C++ the notion of the class is defined the following way class-specifier: class-head { member-specificationopt} where class-head in turn is defined like class-head: class-key attribute-specifier-seqopt class-head-name class-virt-specifieropt base-clauseopt class-key attribute-specifier-seqopt base-clauseopt where class-key: class struct union Thus a structure is class with class-key struct. And (C++Standard 12.1 Constructors) 4...
Understanding Stack Frames in C
The compiler is optimizing away some code in fun2. If you return &a, it is optimizing away int b;. If you return &b, it is optimizing away int a;. If you add some dummy computation, you will see that the addresses of returned values will be different. int * fun2()...
What is the StructLayoutAttribute effect on properties in C#?
Properties have no storage. StructLayoutAttribute does not affect them at all. Auto-properties access a generated backing field which is subject to StructLayoutAttribute (since all fields are subject to this attribute). The order of those fields is not defined however. Since get-properties that just compute a value have no storage they...
Numpy: transpose result of advanced indexing
python,performance,numpy,memory-layout
I would like to sum it along the 0 dimension but in the real world the matrix is huge and I would prefer to be summing it along -1 dimension which is faster due to memory layout. I'm not totally sure what you mean by this. If the underlying...
Cheapest structure for deferencing?
c,performance,data-structures,collections,memory-layout
See solutions categorised below, in terms of pros and cons (thanks to Ruben for assisting my thinking)... I've implemented Option 2 and 5 for my use case, which is somewhat generalised; I recommend Option 4 if you need a very specific, one-off data structure. Option 3 is most flexible while...
understanding of addresses in dynamically loaded library
c,dll,shared-libraries,dynamic-linking,memory-layout
Addresses of functions and variables contained in dynamic loaded libraries are randomized to avoid security breaches.
memory layout of class hierarchy
No this won't work because the sandard says: 9.5/1 : in a union, at most one of the non-static data members can be active at any time that is, the value of at most one of the non-static data members can be stored in a union at any time. What...
Memory layout of globals
No. It is not a reliable assumption that the compiler places the variables in any order or any alignment. There can be gaps between the variables for alignment and I've already seen compilers that order variables alphabetically. If you want to know the pointer to the element that is not...
Casting a POD struct into a derived type
c++,struct,casting,legacy-code,memory-layout
It's certainly not guaranteed to work in general (try adding a virtual function to the derived class), and is formally undefined behavior. (I also don't see how a struct can be used to help transfer data over the network. Different machines will represent it differently.)