[Issue 12891] add atomicInc and atomicDec to core.atomic

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=12891

--- Comment #3 from Martin Nowak <code at dawg.eu> ---
Most likely there is no performance difference between "lock xadd [ptr], 1" and
"lock inc [ptr]", the increment instruction takes a byte less.

You can ask g++/clang++ for good ideas.

----
#include <atomic>

std::atomic<uint8_t> ubyte;
std::atomic<uint16_t> ushort;
std::atomic<uint32_t> uint;
std::atomic<uint64_t> ulong;

int main() {
  ++ubyte;
  ++ushort;
  ++uint;
  ++ulong;
}
----

It seems that we should rather implement the more generic fetch_add and
fetch_sub though.
http://en.cppreference.com/w/cpp/atomic/atomic/fetch_add
http://en.cppreference.com/w/cpp/atomic/atomic/fetch_sub

--