Signed qualifier required for working compile on some systems.

[HPCguy]

No description provided.

[chqrlie]

This patch takes a complicated approach that might not be supported in a simple compiler where the signed keyword can be considered useless. A simpler fix should be:

-    while (std_fns[0] != -1)
+    while (std_fns[0] != '\xff')

'\xx' is negative on platforms where char has 8 bits and is signed by default.

[HPCguy]

It has been a long time since I submitted this.

The only x86 system I have is an HP chromebook [AMD A4-9120C RADEON R4, 5 COMPUTE CORES 2C+3G (2 threads, 1.60GHz)] so I am guessing it was the Chromebook Linux Development Environment GCC compiler I had 'apt install' ed at the time. The only other compiler I have run on that system is https://github.com/EarlGray/c4 , but I highly doubt that was the one I was using. Hence, probably GCC.

[HPCguy]

PS I like your solution better, although I can't test because I have lost the test directory I was using when I had to make the submitted change on this pull request to make the code run. Feel free to close this pull request, but I recommend a fix, because it definitely broke, and took me a minute to figure out why it was crashing in the first place, only to find that my submitted patch made it work.