fix Issue 18251 - deprecate + transition=complex shouldn't look at functions with non-matching if constraints

[ibuclaw]

One workaround for the issue was to put deprecated templates into a code block.

deprecated
{
    auto issue18251(T)(T t)
    if (__traits(isDeprecated, T))
    {
        return T.init;
    }
}

This patch makes it so that the test for issue 18251 has no difference to the above at an AST level.

[dlang-bot]

Thanks for your pull request, @ibuclaw!

Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	18251	normal	deprecate + transition=complex shouldn't look at functions with non-matching if constraints

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#12435"

[ibuclaw]

This function is declared as:

 deprecated string toString()() const { return "42"; }

If you were to change it to...

 deprecated { string toString()() const { return "42"; } }

You'd instead get a deprecation on the template.

So this new diagnostic is correct, as both deprecated template and deprecated { template } now give the same deprecation warning.

[ibuclaw]

Bleh, I'll split this up into three, as it covers a few possibly sensitive areas.

[ibuclaw]

This removal is in-fact related to #12440, no idea how it got auto-merged...

[ibuclaw]

@thewilsonator unblocked and ready.