(j3.2006) derived types with type parameters are different

Aleksandar Donev donev1
Thu Jul 24 13:36:06 EDT 2008

Jim Xia wrote:
> For two sequence types to be the same type, they 
> must have the same memory layout for any pair of objects that having the 
> same type parameter values.
Wow, are you serious. Does the IBM compiler now implement a Maple 
symbolic algebra proof (reduction) system???
Seriously, we cannot possibly add ANY burden on compilers due to this 
"over-integration". The equivalence of SEQUENCE types is an old 
"feature" which has little to no place in modern programming. Using it 
with derived type parameters should certainly not be encouraged, yet 
alone glorified by forcing any compiler to do more work than necessary.

If there is no words in the standard, Robert should submit an interp.

I would say that two separate derived types with parameters are never 
equivalent even if they are SEQUENCE, even if they are cut-and-pasted.


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