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As long as the stack frame is still active, the local variables are still alive and valid. So you could pass a local function as a parameter, but you could not return it. I think jwz called these "downward funargs".

GCC supports it http://gcc.gnu.org/onlinedocs/gcc/Nested-Functions.html

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GCC's nested functions are implemented with trampolines, so there will be a performance penalty. For the amount that you gain, they seem like a bad idea. Tying your code to GCC for the sake of a small amount of convenience is a bad idea.

With things like PaX the trampoline method won't work, gcc now creates thunks, which are essentially heap allocated thunks of memory (hence the name) with PROT_EXEC.

The question to which I responded did not inquire about performance nor about portability

http://tirania.org/blog/archive/2011/Feb-17.html

My comment was about GCC's local functions. It wasn't really about your comment, so I regret if you took it personally.

Thank you. Much respect, sorry if I was harsh.

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