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yohhoy/vlafib.c

Last active July 5, 2022 10:27
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Fibonacci with VLA on C99
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vlafib.c
#include <stdio.h>
size_t f(size_t, char [][*]);
size_t f(size_t n, char r[][2 < n ? f(n-2, 0) + f(n-1, 0) : 1])
{
return sizeof(*r);
}
int main()
{
printf("%zu\n", f(10, 0)); // 55
}
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yohhoy commented Dec 2, 2017

This is UB. See https://stackoverflow.com/questions/32985424/is-the-operand-of-sizeof-evaluated-with-a-vla/

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