4 ms·

In C++ because of how it developed the defaults are not optimal. For example, constructors and conversions are implicit and you have to make them explicit. Vari

• JTyQZSnP3cQGa8B 2y ago
  > Variables are default mutable and you have to make them const Except for the captured variables in a lambda which are const unless you use the mutable keyword. Not a bad idea though.
  • Maxatar 2y ago
    And that's only true if you capture by value. If you capture by reference they remain mutable.
    • chombier 2y ago
      I think this is because `mutable` qualifies the call operator of the lambda (like a reverse const qualifier) so by-value captures are effectively const during the call unless the lambda is marked `mutable`. References themselves are always const, but the referenced object may be modified through the reference depending on its constness even though the lambda is not `mutable`. Is there a way to force capture by const-reference by the way?
      • gpderetta 2y ago
        int main() { int x = 0; [&x] { x= 1;}(); // works [&x=std::as_const(x)] { x= 1;}(); // error: assignment of read-only reference 'x' } Not very pretty, but it works.