If you know what you’re doing, you can make a vector of references using std::reference_wrapper: #include <functional> #include <vector> int main() { std::vector<std::reference_wrapper<int>> iv; int a = 12; iv.push_back(a); // or std::ref(a) // now iv = { 12 }; a = 13; // now iv = { 13 }; } Note of course that any … Read more
In C++11, you should add rvalue reference: A(A&&); void operator=(A&& a );
When in doubt, pass by value. Now, you should only rarely be in doubt. Often values are expensive to pass and give little benefit. Sometimes you actually want a reference to a possibly mutating value stored elsewhere. Often, in generic code, you don’t know if copying is an expensive operation, so you err on the … Read more
The construct of INDEX() >>:<<INDEX() will work when applied to ranges. Not to arrays AFAIK. It will lead to these errors. Maybe try something like: =LET(range,A1:D2,MAKEARRAY(ROWS(range),COLUMNS(range),LAMBDA(r,c,SUM(INDEX(range,r,SEQUENCE(c)))))) This would resemble the construct of your inital formula. However, in the linked question you have mentioned that you’d like to use SCAN() in combination with BYROW(). You have … Read more
The issue has little to do with STL, and everything to do with passing objects across application boundaries. 1) The DLL and the EXE must be compiled with the same project settings. You must do this so that the struct alignment and packing are the same, the members and member functions do not have different … Read more
This looks like it could be a bug – probably in DynamicObject. If you add a Wrap method to Proxy like this: public void Wrap(ref int x, ref int y) { target.Swap(ref x, ref y); } Then even though this is still called dynamically (i.e. the code in Main stays the same) the code works… … Read more
What I don’t understand is what happens when I invoke a method, what actually happens. Does new() get invoked? Does it just automagically copy the data? Or does it actually just point to the original object? And how does using ref and out affect this? The short answer: The empty constructor will not be called … Read more
You cannot bind a literal to an lvalue reference to non-const (because modifying the value of a literal is not an operation that makes sense). You can however bind a literal to a reference to const. So this will compile if you declare fillRect as: void fillRect(int const& x, int const& y, int const& width, … Read more
This is a more general answer for future viewers. Callback types There are a few different types of predefined callbacks: final VoidCallback myVoidCallback = () {}; final ValueGetter<int> myValueGetter = () => 42; final ValueSetter<int> myValueSetter = (value) {}; final ValueChanged<int> myValueSetter = (value) {}; Notes: VoidCallback is an anonymous function that takes no arguments … Read more
What you are after is called partial function application. Don’t be fooled by those that don’t understand the subtle difference between that and currying, they are different. Partial function application can be used to implement, but is not currying. Here is a quote from a blog post on the difference: Where partial application takes a … Read more