[PATCH] D56035: Provide storage for `true_type::value` and `false_type::value`.

[Dan Liew via Phabricator via llvm-commits]

delcypher added inline comments.


================
Comment at: lib/sanitizer_common/sanitizer_type_traits.cc:17
+namespace __sanitizer {
+const bool true_type::value;
+const bool false_type::value;
----------------
vitalybuka wrote:
> I guess we can avoid cc file if you use constexpr in the header file.
@vitalybuka I tried that. Unfortunately I still get link errors.

See https://stackoverflow.com/questions/8452952/c-linker-error-with-class-static-constexpr .

An alternative to this patch to just change the test that causes the problem to something like

```
ASSERT_TRUE(bool(is_same<uptr, uptr>::value));
````

This avoids taking a reference to `is_same<T,U>::value` and instead constructs a temporary value from it. The `ASSERT_TRUE` macro then takes a reference to it.

I'm not sure which is better. Changing the test just hides the issue (it will occur again if anyone tries to take a reference to `is_same<T,U>::value`). However this patch bloats the code for the purpose of a single test, which isn't great either.

Let me know, which you'd prefer.


Repository:
  rCRT Compiler Runtime

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D56035/new/

https://reviews.llvm.org/D56035