memcpy() comparison: C, Rust, and D

[Jack Stouffer via Digitalmars-d]

On Tuesday, 31 January 2017 at 01:30:48 UTC, Walter Bright wrote:
> 2. The return value is derived from s1.
> 4. Copies of s1 or s2 are not saved.

Actually I didn't know either of those things from looking at the 
signature because DIP25 and DIP1000 have marketing problems, in 
that the only way to get info on them is on the DIP pages. I'd be 
willing to bet money that 80% of the people who use D don't know 
about the -dip25 flag.

Is there anywhere which gives a simple explaination of both of 
these DIP's safety checks?