checkedint call removal

[David Bregman via Digitalmars-d]

On Wednesday, 30 July 2014 at 03:32:50 UTC, Walter Bright wrote:
> I don't either. I still have no idea what the difference 
> between assume(i<6) and assert(i<6) is supposed to be.

assert:
is a runtime check of the condition.
is a debugging/correctness checking feature.
is used when the expression is believed true, but is not proven 
so.
(if it was proven, then there is no purpose in asserting it with 
a redundant runtime check that is guaranteed to never activate.)

assume:
passes a hint to the optimizer to allow better code generation.
is used when the expression is proven to be true (by the 
programmer, like @trusted).

The only relation between the two is that if a runtime check for 
(x) is inserted at some point, it is safe to insert an assume(x) 
statement afterwards, because x is known true at that point.

If assert degenerates to assume in release mode, any bugs in the 
program could potentially cause a lot more brittleness and 
unexpected/undefined behavior than they otherwise would have. In 
particular, code generation based on invalid assumptions could be 
memory unsafe.