How To Implement Closures?

As I understand, closures could be unboxed using a generated trampoline, like
mov rax, qword 12345678ABCDEFh ; 10 bytes function address
jmp rax ; 2 bytes
payload times N db 0 ; closure environment

Won't that mess code cache?

OSX disallows both WRITE and EXEC access. When you write C/C++ you're a professional, who know what he is doing, so such patronizing is an insult. Moreover, security is hyped and always gets in the ways, especially when compiler starts spitting warnings like gets() is obsolete. I know better what is obsolete, okay?