On Fri, 9 Jan 2015, Simon Wright wrote:

>> The first 2 cases produces an error during the build, as expected,
>> because Head is known to be length of 5 and I'm assigning something of
>> a different length.

I believe, all three should generate a run-time error (most likely a 
Constraint_Error).

But a good compiler should also warn you about the run-time error, and 
maybe you have set your compiler to treat warnings as errors (which is
not a bad idea).

>> The 3rd assignment there does NOT produce an error, no warning no
>> nothing even though this clearly violates the same check.

This is a compiler bug!


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