This smol post assumes you worked on a custom thunk implementation before but no idea how it works, why you're using cursed macros from 1990s etc. If you don't have any programming experience or relatively new to Unreal world, it's likely you might not understand anything from this post, not because concepts are too difficult to grasp, but rather because this post is written for the people who has an understanding of how Unreal works since a while and want to expand their knowledge of custom thunks implementation.

• A thunk is a function that you can save and call later, so if you had an array of TFunction<void()>s, you would have an array of custom thunks that you can bind/unbind new function pointers to existing TFunctions.
• Custom thunks of Blueprints are the same, they're a fancy array/list of function pointers. Imagine for each node you placed to graph, Blueprints have a place for that node in it's list of custom thunks. For example the + node in Blueprints that

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

I recently happened upon an implementation of popen() (different API, same idea) using clone(2), and so I opened an issue requesting use of vfork(2) or posix_spawn() for portability. It turns out that on Linux there's an important advantage to using clone(2). I think I should capture the things I wrote there in a better place. A gist, a blog, whatever.

So here goes.

Long ago, I, like many Unix fans, thought that fork(2) and the fork-exec process spawning model were the greatest thing, and the Windows sucked for only having [exec*()](http://pubs.opengroup.org/onlinepubs/9699919