[Issue 20687] Allow member function address as const initializer

Mar 19, 2020

Dlang Bot

Mar 20, 2020

Mar 22, 2020

Mar 22, 2020

Mar 22, 2020

Mar 23, 2020

Mar 28, 2020

Apr 12, 2020

Apr 21, 2020

Apr 21, 2020

Dec 17, 2022

May 10, 2023

https://issues.dlang.org/show_bug.cgi?id=20687 Dlang Bot <dlang-bot@dlang.rocks> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |pull --- Comment #1 from Dlang Bot <dlang-bot@dlang.rocks> --- @BorisCarvajal created dlang/dmd pull request #10946 "Fix Issue 20687 - Allow member function address as const initializer" fixing this issue: - Fix Issue 20687 - Allow member function address as const initializer https://github.com/dlang/dmd/pull/10946 --

https://issues.dlang.org/show_bug.cgi?id=20687 --- Comment #3 from Dlang Bot <dlang-bot@dlang.rocks> --- dlang/dmd pull request #10948 "Revert "Fix Issue 20687 - Allow member function address as const initializer"" was merged into stable: - bb766e125c590249730f967892bda6697b4a648b by Iain Buclaw: Revert "Fix Issue 20687 - Allow member function address as const initializer" https://github.com/dlang/dmd/pull/10948 --

https://issues.dlang.org/show_bug.cgi?id=20687 Mathias LANG <pro.mathias.lang@gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED CC| |pro.mathias.lang@gmail.com Resolution|FIXED |--- --- Comment #4 from Mathias LANG <pro.mathias.lang@gmail.com> --- This has been re-opened, as it is not clear whether we want it to be possible or not. The fact it's possible at runtime could be considered an accept-invalid, instead of this being a reject-valid. --

March 22, 2020

[Issue 20687] Allow member function address as const initializer

Posted by Steven Schveighoffer

Permalink

Steven Schveighoffer

Permalink

https://issues.dlang.org/show_bug.cgi?id=20687

Steven Schveighoffer <schveiguy@yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |schveiguy@yahoo.com

--- Comment #5 from Steven Schveighoffer <schveiguy@yahoo.com> ---
It's very clear to me it should be available at compile time and runtime. Whether it is callable on its own is a matter for debate, but that would be a breaking change.

If we made it unavailable at runtime, it is still available with &instance.fun.funcptr. What does funcptr return? If we started disallowing funcptr manipulation, then maybe this becomes invalid, but that is a whole new ball of code breakage that I don't think we want to get into right now.

Even if we disallowed creating a variable that accepts such a member-function pointer, a delegate has no type information for it's context pointer, so something like this would still be possible:

struct S
{
  int x;
  void foo() {++x;}
}

struct T
{
  int *x;
  void bar() {*x = 5;}
}

auto s = S(100000);
T t;
auto dg = &s.foo;
dg.funcptr = (&t.bar).funcptr;

dg(); // uses s.x as if it were a pointer

If we wanted to talk about type safety in this area, the status quo does not cut it. While not type-safe, at least it can be made consistent.

--

https://issues.dlang.org/show_bug.cgi?id=20687 --- Comment #6 from Dlang Bot <dlang-bot@dlang.rocks> --- @BorisCarvajal created dlang/dmd pull request #10958 "Fix Issue 20687 - Allow member function address as const initializer" fixing this issue: - Fix Issue 20687 - Allow member function address as const initializer https://github.com/dlang/dmd/pull/10958 --

https://issues.dlang.org/show_bug.cgi?id=20687 --- Comment #7 from Dlang Bot <dlang-bot@dlang.rocks> --- @MoonlightSentinel created dlang/dmd pull request #10970 "Merge branch 'master' into stable" fixing this issue: - Fix Issue 20687 - Allow member function address as const initializer - Merge pull request #10946 from BorisCarvajal/mptr_constinit Fix Issue 20687 - Allow member function address as const initializer merged-on-behalf-of: Nicholas Wilson <thewilsonator@users.noreply.github.com> - Revert "Fix Issue 20687 - Allow member function address as const initializer" https://github.com/dlang/dmd/pull/10970 --

https://issues.dlang.org/show_bug.cgi?id=20687 --- Comment #8 from Dlang Bot <dlang-bot@dlang.rocks> --- @MartinNowak created dlang/dmd pull request #11027 "merge stable" fixing this issue: - Fix Issue 20687 - Allow member function address as const initializer - Merge pull request #10946 from BorisCarvajal/mptr_constinit Fix Issue 20687 - Allow member function address as const initializer merged-on-behalf-of: Nicholas Wilson <thewilsonator@users.noreply.github.com> - Revert "Fix Issue 20687 - Allow member function address as const initializer" https://github.com/dlang/dmd/pull/11027 --

https://issues.dlang.org/show_bug.cgi?id=20687 Dlang Bot <dlang-bot@dlang.rocks> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution|--- |FIXED --- Comment #9 from Dlang Bot <dlang-bot@dlang.rocks> --- dlang/dmd pull request #11027 "merge stable" was merged into master: - 4ad1a199e2d5a9a0b87b1513e5690b9e29a8ed54 by Boris Carvajal: Fix Issue 20687 - Allow member function address as const initializer - aba2deaefdd3bb0ce9d3293b715959a6de416679 by The Dlang Bot: Merge pull request #10946 from BorisCarvajal/mptr_constinit Fix Issue 20687 - Allow member function address as const initializer merged-on-behalf-of: Nicholas Wilson <thewilsonator@users.noreply.github.com> - 1f3245d3241d90f4d74b9398558ddc71d57335c4 by Iain Buclaw: Revert "Fix Issue 20687 - Allow member function address as const initializer" https://github.com/dlang/dmd/pull/11027 --

Forums