Function Subspace :: sus :: ptr :: copy_nonoverlapping
!std::is_const_v<T>
Copies count * size_of<T>() bytes from src to dst. The source and
destination must not overlap.
For regions of memory which might overlap, use copy
instead.
copy_nonoverlapping is semantically
equivalent to
memcpy, but with the argument order swapped.
The copy is “untyped” in the sense that data may be uninitialized or
otherwise violate the requirements of T. The initialization state is
preserved exactly.
Panics
This function will panic if the number of bytes, count * size_of<T>(),
overflows.
Safety
Behavior is undefined if any of the following conditions are violated:
srcmust be valid for reads ofcount * size_of<T>()bytes.dstmust be valid for writes ofcount * size_of<T>()bytes.- The region of memory beginning at
srcwith a size ofcount * size_of<T>()bytes must not overlap with the region of memory beginning atdstwith the same size. dstmust not have an overlapping object in its tail padding. Ifdstis in an array, or was heap allocated, then this will always be satisfied.
Like copy,
copy_nonoverlapping creates a bitwise
copy of T,
regardless of whether T is TrivialCopy
or TriviallyRelocatable. If T
is not TrivialCopy, using the value in
*dst can violate memory safety.
If T is not TriviallyRelocatable,
using both the values in *src and in *dst can violate memory safety.
Note that even if the effectively copied size (count * size_of<T>()) is 0,
the pointers must be non-null and properly aligned.