Making alloca more safe

[bearophile]

Walter Bright:

> A person using alloca is expecting stack allocation, and 
> that it goes away after the function exits. Switching arbitrarily to the 
> gc will not be detected and may hide a programming error (asking for a 
> gigantic piece of memory is not anticipated for alloca, and could be 
> caused by an overflow or logic error in calculating its size).

There's another solution, that I'd like to see more often used in Phobos: you can add another function to Phobos, let's call it salloca (safe alloca) that does what Denis Koroskin asks for (it's a very simple function).

Bye,
bearophile