Make TempStringNoAlloc a template

[skoppe]

Fixes https://issues.dlang.org/show_bug.cgi?id=20088

Since the new __ArrayCast template hook, casting arrays is broken in betterC. The reason is that __ArrayCast indirectly depends on TempStringNoAlloc.get, which is not a template function and doesn't get linked in betterC.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	20088	blocker	void[] cast unusable in betterC due to new __ArrayCast template

Testing this PR locally

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

dub fetch digger
dub run digger -- build "stable + druntime#2705"

[thewilsonator]

Please add the test case from the bug report.

[PetarKirov]

In Phobos we have the option to run @betterC unit tests, and I think we should set up something like that for druntime as well - see:
dlang/phobos#5952.
In the mean time, you can add a test to Phobos as well.
Nevermind, the test you added looks good.

[skoppe]

In Phobos we have the option to run @betterC tests, and I think we should set up something like that for druntime as well. In the mean time, you can add a test to Phobos as well

Sure, but what would be the benefit? Plus, where do you want me to put it? Ok.

[wilzbach]

Test fails with:

generated/linux/release/64/test20088.o: In function `_D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv':
src/test20088.d:(.text._D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv[_D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv]+0x5e): undefined reference to `_D4core8internal6string17TempStringNoAlloc__T3getZQfMFNaNbNiNjNfZAa'
src/test20088.d:(.text._D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv[_D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv]+0x9e): undefined reference to `_D4core8internal6string17TempStringNoAlloc__T3getZQfMFNaNbNiNjNfZAa'
collect2: error: ld returned 1 exit status

In Phobos we have the option to run @BetterC unit tests, and I think we should set up something like that for druntime as well - see:

@betterC should be a thing soon here as well (e.g. #2715).

[skoppe]

Test fails with:

generated/linux/release/64/test20088.o: In function `_D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv':
src/test20088.d:(.text._D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv[_D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv]+0x5e): undefined reference to `_D4core8internal6string17TempStringNoAlloc__T3getZQfMFNaNbNiNjNfZAa'
src/test20088.d:(.text._D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv[_D6object__T16onArrayCastErrorZQtFNaNbNiNeAyamQemZv]+0x9e): undefined reference to `_D4core8internal6string17TempStringNoAlloc__T3getZQfMFNaNbNiNjNfZAa'
collect2: error: ld returned 1 exit status

Hmm, I see. Will look into it this weekend.

[skoppe]

@wilzbach I found the mistake. Some CI's are still red though, but it doesn't seem to be caused by my changes. Would it help if I rebase on stable again?

[wilzbach]

Would it help if I rebase on stable again?

Probably. Just tried this for you.

[thewilsonator]

Appveyor is expected to fail on stable.