Re: Multiple assignment attempt crashes gnu-apl

[PAUL ROCKWELL]

I've been able to reproduce this with macOS 10.15 Catalina and the Command Line 
tools for Xcode 12.4 (the last version that ran on Catalina).

The macOS c++ (clang) compiler seems to default to a C++ dialect of gnu++98. 
Using this dialect, the generated interpreter compiles, but throws the 
assertion failure for the assignment (a b c) ← 5.

I have been able to work around this. Choosing a more recent C++ dialect (which 
matches the default dialect in the GCC compilers on Linux) seems to address the 
issue. 

If you run 

./configure -CXXFLAGS="-std=gnu++14" 

then build the interpreter, the resulting interpreter runs the assignment as 
expected, and the assertion is not thrown. 

Is there a minimum dialect of C++ that should be used to compile GNU APL?

- Paul Rockwell