Questionable g++ behaviour

[Arthur Pemberton]

I am by no means a guru in C++, so I come to the list to ask advice. I have
been informed that C++ does not allow for array declarations using varaibles
as the size parameter:

<data_type> <array_name>[<variable>]

Yet g++ clearly allows this. Is this my misunderstanding? If so, can anyone
point me in the direction of the appropriate C++ specs so that I may use as
evidence? Or is this a bug or gotcha in g++? If so, should I file a bug
report?

I have attached a sample .cpp which compiles and runs for me.

Thank you.
--
As a boy I jumped through Windows, as a man I play with Penguins.