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digitalmars.D.learn - Error: incompatible types for 'shared(SysTime)' and 'shared(SysTime)'

reply Luke Picardo <Picardo12 mail.com> writes:
if (curTime - lastMsgTime).total!"seconds") ...

Both are shared Durations.

also when I try to do

lastMsgTime = curTime;

Gives me

Error: non-shared method std.datetime.SysTime.opAssign is not 
callable using a shared object.
Jul 04 2016
parent reply ketmar <ketmar ketmar.no-ip.org> writes:
On Monday, 4 July 2016 at 20:54:53 UTC, Luke Picardo wrote:

 if (curTime - lastMsgTime).total!"seconds") ...

 Both are shared Durations.

 also when I try to do

 lastMsgTime = curTime;

 Gives me

 Error: non-shared method std.datetime.SysTime.opAssign is not 
 callable using a shared object.


cast `shared` away. yes, this is how you supposed to use it now: 
cast it away.
Jul 04 2016
parent reply ag0aep6g <anonymous example.com> writes:
On 07/05/2016 07:25 AM, ketmar wrote:

 cast `shared` away. yes, this is how you supposed to use it now: cast it
 away.


after having ensured thread safety that is
Jul 05 2016
parent reply Arafel <er.krali gmail.com> writes:
On 07/05/2016 04:16 PM, ag0aep6g wrote:

 On 07/05/2016 07:25 AM, ketmar wrote:

 cast `shared` away. yes, this is how you supposed to use it now: cast it
 away.


 
 after having ensured thread safety that is


Sorry to resurrect an old thread, but then how can one update a SysTime 
field in a shared class? Like this (using a synchronized class for 
simplicity, this part works and the mutex acts as expected):

```
import std.concurrency;
import std.datetime.systime;

import core.thread;

public synchronized shared class A {
     public:
     void doSomething() {
         // Doing something takes a couple of seconds.
         Thread.sleep(2.dur!"seconds");

         // How can we update the timestamp? Neither of those work
         timestamp = Clock.currTime;
         timestamp = cast(shared) Clock.currTime;
     }
     private:
     SysTime timestamp;
}

void main() {
     shared A a = new shared A;
     spawn( (shared A a) { a.doSomething;}, a );
     Thread.sleep(1.dur!"seconds");
     spawn( (shared A a) { a.doSomething;}, a );
}
```

Of course the kludge (and what I'll be doing) is just to use __gshared, 
but I expected this to be a convenience / hack to save you castings, 
rather than the only way to achieve it.

A.
Sep 13 2018
parent reply ag0aep6g <anonymous example.com> writes:
On 09/13/2018 03:25 PM, Arafel wrote:

          // How can we update the timestamp? Neither of those work
          timestamp = Clock.currTime;
          timestamp = cast(shared) Clock.currTime;


cast() timestamp = Clock.currTime;
Sep 13 2018
parent reply Arafel <er.krali gmail.com> writes:
On 09/13/2018 06:59 PM, ag0aep6g wrote:

 On 09/13/2018 03:25 PM, Arafel wrote:

          // How can we update the timestamp? Neither of those work
          timestamp = Clock.currTime;
          timestamp = cast(shared) Clock.currTime;


 
 cast() timestamp = Clock.currTime;


Still not there... it doesn't work with ref parameters (and probably 
other things, like AAs, or at least nested AAs / arrays):

```
import std.stdio;
import std.datetime.systime;
import core.time;

void foo(ref SysTime t) {
     t += 1.dur!"minutes";
}

shared synchronized class A {
     private SysTime s;

     this() {
         cast ()s = Clock.currTime; // OK, This works
     }

     void foo() {
         writeln("A.foo - Before: ", cast() s);

         // But how to do this??
         //(cast () s).foo;
         //s.foo;

         writeln("A.foo - After: ", cast() s);
     }
}

void main() {

     SysTime s = Clock.currTime;
     writeln("main - Before: ", s);
     s.foo;
     writeln("main - After: ", s);

     shared A a = new shared A;
     a.foo;
}
```

That makes me wonder if casting a lvalue makes sense at all, and how 
come that the result is not another lvalue... what it is, I don't know, 
because you can assign to it, but not take a reference.
Sep 14 2018
parent Arafel <er.krali gmail.com> writes:
(*(cast (SysTime*) (&s))).foo;

Not exactly obvious or user-friendly...
Sep 14 2018