On Thursday, 15 August 2019 at 19:51:30 UTC, Jonathan M Davis
wrote:
n Thursday, August 15, 2019 11:33:06 AM MDT Piotr Mitana via
Digitalmars-d- learn wrote:
Code:
import std;
shared(string[string]) dict;
void main()
{
dict.keys;
}
Error:
/dlang/dmd/linux/bin64/../../src/druntime/import/object.d(3417):
Error: cannot implicitly convert expression aa of type
shared(string[string]) to const(shared(string)[string])
onlineapp.d(7): Error: template instance
`object.keys!(shared(string[string]), shared(string), string)`
error instantiating
Before D 2.087 it compiled - is this a regression?
Not being able to implicitly convert to const is a bit odd, but
arguably, nothing should ever be called on a shared AA anyway.
If an operation isn't thread-safe, then it shouldn't work with
shared. To use a shared object safely, you have to protect
access to it with a mutex or some other synchronization
mechanism, after which you would normally cast away shared to
operate on the object as thread-local while the lock is in
place and then release the lock when you're done (also making
sure that no thread-local references exist when the lock is
released). Because keys is not at all thread-safe, I'd strongly
argue that it should not work on a shared AA, and if it does,
that's a bug.
- Jonathan M Davis
D really needs some official thread-safe implementations of
containers, hashmaps etc.
