enable_if error about xivo

[stephanietsuei]

I have never compiled xivo on any MacOS, but it looks like you are using a C++ compiler that doesn't support a particular language feature that we use. So far, we've only tested xivo using g++-7 and Ubuntu 16.04 and Ubuntu 18.04.

[stephanietsuei]

For the sake of remote work, we're going to fix this. So far, this is what we see:

• No error using gcc-7 (deprecated, because Ubuntu 16.04 is EOL) and gcc-8 (not deprecated, because Ubuntu 18.04 is not yet EOL) on Ubuntu 20.04
• Error using gcc-9 on Ubuntu 20.04
• Error using gcc-11 on Manjaro/Arch Linux
• Error on Mac OS Catalina

@agrawalparth10, I'll get it working on the later versions of gcc first. Then I'll have you test on whatever version of Mac OS you're using.

[stephanietsuei]

I think this is fixed in commit 6be7826. Current status:

• Tested and runs on Ubuntu 20.04 using gcc-9.
• Still works on Ubuntu 20.04 using gcc-8.
• Can't be tested on Manjaro/Arch until we address issue #27.
• No idea on Mac OS.

[agrawalparth10]

Okay, I will try to compile it today

[stephanietsuei]

Addressed in #28