On 9/17/2014 12:30 AM, monarch_dodra wrote:
On Wednesday, 17 September 2014 at 07:21:13 UTC, Andrej Mitrovic via
Digitalmars-d wrote:
On 9/17/14, bearophile via Digitalmars-d <digitalmars-d@puremagic.com> wrote:
Andrei Alexandrescu:
Add a sequence number as a uint, defaulted to 0. -- Andrei
See discussion:
https://d.puremagic.com/issues/show_bug.cgi?id=12100
It's a good thing you found GCC and VC implement this. I think it's
another sign that we could use this feature.
Technically, they implement it via macro, and the macro re-expands on every use.
It's mostly useless outside of ".cpp" files: The identifiers are unstable cross
compilation units. And if it appears in a .h, it'll be re-expanded to a
different value on every include. If it appears in a macro, it'll be expanded to
something different on every macro use too.
It's implemented as a special macro named __COUNTER__ which expands to an
integer literal, incremented each time.
If such a thing were implemented in D, one could not depend on the values being
globally unique, nor consistent when a module is compiled vs imported, nor
consistent when multiple modules are compiled together vs compiled
independently, nor even any predictable relationship between the values within a
particular module (because semantic analysis is not supposed to be order dependent).
