When an alias is passed inside a template, is(symbol == template) should work to test whether the symbol is a template.
https://github.com/D-Programming-Language/dmd/pull/1239
https://github.com/D-Programming-Language/dmd/pull/3380
Commits pushed to master at https://github.com/D-Programming-Language/dmd https://github.com/D-Programming-Language/dmd/commit/8bebbe4845b8a5f5ebaa87f52b2c9a0a42c3a46e Fixes Issue 1673 - Implement the isTemplate trait. https://github.com/D-Programming-Language/dmd/commit/c5b285d59edbab3e5ada6aefff8de40c4a399fb1 Merge pull request #3380 from AndrejMitrovic/isTemplate Issue 1673 - Implement the isTemplate trait.
dlang/dub pull request #2034 "Correct issue #1673 (with dupe #1797 and #2019)" was merged into master: - 4e2dd8530dac9a209e6beeac0e0f789e09b7eaf8 by Guillaume Piolat: Correct issue #1673 (with dupe #1797 and #2019) https://github.com/dlang/dub/pull/2034