Not really modern, it is Object Pascal/Modula-2 repackaged in C like syntax.
The only thing relatively modern would be compile time execution, if we forget about how long some languages have had reader macros, or similar capabilities like D's compile time metaprogramming.
Also it is the wrong direction when the whole industry is moving into integrity by default on cyber security legislation.
There are several examples around of doing arenas in said languages.
https://dlang.org/phobos/std_experimental_allocator.html
You can write your own approach with the low level primitives from Swift, or ping back into the trusty NSAutoreleasePool.
One example for C#, https://github.com/Enichan/Arenas