MSVC 2015's SFINAE implementation is broken. In particular, it seems not
to bother expanding EnableIfContainer unless we force it to by writing
::type. That means we need to use std::enable_if rather than
enable_if_t, even though it's quite wordy.
Change-Id: Ic643ab8a956991bb14af07832be80988f7735428
Reviewed-on: https://boringssl-review.googlesource.com/20764
Commit-Queue: Martin Kreichgauer <martinkr@google.com>
Reviewed-by: Martin Kreichgauer <martinkr@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>