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cdcbafc835
gcc -std=c++20 (but not clang -std=c++20) complains about template class definitions that specify the template parameter on the class constructor. For example:
template <typename T>
class C {
C(int x) {}
// OK in clang and gcc for both -std=c++17 and -std=c++20.
C<T>(int x, int y) {}
// OK in clang for both -std=c++17 and -std=c++20.
// OK in gcc -std=c++17 but a build error with -std=c++20.
};
The ipc/chromium build error because the `DISALLOW_COPY_AND_ASSIGN` macro expands to such a template class definition:
ipc/chromium/src/base/basictypes.h:53:12: error: expected unqualified-id before 'const'
| TypeName(const TypeName&) = delete
| ^~~~~
ipc/chromium/src/base/threading/thread_local.h:95:3: note: in expansion of macro 'DISALLOW_COPY_AND_ASSIGN'
| DISALLOW_COPY_AND_ASSIGN(ThreadLocalPointer<T>);
| ^~~~~~~~~~~~~~~~~~~~~~~~
Google replaced chromium/base's DISALLOW_COPY_AND_ASSIGN macros with explicitly deleted constructors, so let's apply their upstream fix:
7319bbdb7d
Differential Revision: https://phabricator.services.mozilla.com/D150216