Big Clod, Tiny 🎈 @wallhackio@cat.family

@vaporeon_ did you know that std::endl not only adds a newline but also inexplicably calls a method on the underlying "output stream instance" representing the console output, meaning that writing std::cout << "Hello world" << std::endl is less performant than writing std::cout << "Hello world" << "\n";?

@vaporeon_ T&& is an "rvalue reference to T" which is a whole can of worms I am not going to explain right now

@vaporeon_ not object-oriented but still pretty bad

@aescling @vaporeon_ lmao

@aschmitz @aescling @vaporeon_ today you are my favorite masto user who username's first syllable sounds like "ash"

@vaporeon_ someone in a reddit comment said they actually saw this in their company's production code so even if its wrong, its out in the wild somewhere

@aescling @vaporeon_ forgive me for not knowing what i am talking about

@vaporeon_ i have failed in my objective lol

@vaporeon_ lmao

@vaporeon_ it's from an openssl library: https://docs.openssl.org/1.0.2/man3/rand/

@vaporeon_ maybe it needs to be in the main function

@vaporeon_ I got it from https://www.reddit.com/r/cpp/comments/1hefgfn/what_are_your_best_niche_c_fun_facts/m23pxj0/

@vaporeon_ you have already put more thought into that hack than i ever have by writing this comment

@vaporeon_ (tbh i also kinda like it)

@vaporeon_ i must be misremembering what i saw. i'm trying to find it but i can't. for now just forget about that one

@vaporeon_ I don't know what this is doing but it looks evil:

const char* seed = "random seed";
RAND_seed(seed, sizeof(seed));

The following snippet which assigns to an rvalue, something you're not supposed to be able to do:

#include <iostream>
class A{};
int main() {
  const A a;
  std::cout << &(A() = a) << "\n"; 
}

using the ternary operator to conditionally change what variable is assigned to:

int main() {
  int a;
  int b;

  // do stuff, also assign to a and b

  (a < b ? a : b) = 3;  
}

The following is actually valid C++ code:

https://www.google.com

Operator overloading lets you do plenty of absurdities. You could, for example, override <= such that it behaves like a "move assignment":

class A {
public:
  int num;

  A& operator<=(A& other) {
    this->num = other.num;
    return *this;
  }
};

int main() {
  A a;
  A a2;

  a.num = 1000;

  a2 <= a;  // move a's content to a2
};

There's certainly more but this is plenty of evil shit.

@vaporeon_ :

@monorail