ctfeexpr: support reinterpreting cast when switching safe/pure/nothrow in both directions

[ljmf00]

Signed-off-by: Luís Ferreira contact@lsferreira.net

[UplinkCoder]

allowing this cast breaks the type system

[UplinkCoder]

Where's the bugreport which requests this?

[ljmf00]

allowing this cast breaks the type system

Yes. Although, AFAIK CTFE engine can handle these cases. Some functions on standard library use assumePure that does this type of casts. I can do further testing to see if this is viable.

[ljmf00]

Where's the bugreport which requests this?

There's no bug report for this, atm.

[MoonlightSentinel]

There's no bug report for this, atm.

Please create a new one or add a changelog entry

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	21997	enhancement	CTFE should allow function pointer casts with different attributes

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#12514"

[MoonlightSentinel]

Added a bugzilla reference and slightly extended the test case

[ljmf00]

Added a bugzilla reference and slightly extended the test case

I'm so sorry for not answering quickly. As I mentioned previously here, dlang/dlang.org#2946 (comment), I'm very busy due to school stuff.

[MoonlightSentinel]

No worries, I just wanted to have these changes to enable dlang/druntime#3494.

[tom-tan]

Can we extend the same idea to other interpreting casts?
For example, CTFEability of casting from immutable to mutable is one of blockers of issue 21405.

[ljmf00]

Can we extend the same idea to other interpreting casts?
For example, CTFEability of casting from immutable to mutable is one of blockers of issue 21405.

I can look at this when I have some time.

[JohanEngelen]

https://issues.dlang.org/show_bug.cgi?id=22186