GitLab

GCC doesn't like that the Value data member has no out-of-line
definition. The problem is triggered specifically only when compiling

  components/services/leveldb/leveldb_database_impl.cc

which has lambda functions returning locally-defined classes.

The current code works as-is in C++17 mode which introduces the concept
of inline variables, but in C++14 we need either an explicit out-of-line
definition or a function member instead of a data member.

Use std::integral_constant for defining the value.

Bug: 819294
Change-Id: I5c68e14ce3fa9d8b4d8a2cb42d7f9b53938aabf3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1862451Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Jüri Valdmann <juri.valdmann@qt.io>
Cr-Commit-Position: refs/heads/master@{#706384}