ambigulity: unknown type name 'nullptr_t'

[xwnb]

Signed-off-by: xwnb xwnbzc@outlook.com

When build ros2/demos image_tools on Ubuntu, a compile error occurred (using clang). Looks like the nullptr_t causes ambiguous between std::nullptr_t and cv::nullptr_t.

error:

error: unknown type name 'nullptr_t'

compile command:

colcon build --cmake-force-configure --symlink-install

system version:

Linux version 5.8.0-59-generic (buildd@lcy01-amd64-022) (gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #66~20.04.1-Ubuntu SMP Thu Jun 17 11:14:10 UTC 2021

clang version:

clang version 10.0.0-4ubuntu1
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

[clalancette]

It seems reasonable to me. According to https://en.cppreference.com/w/cpp/types/nullptr_t, nullptr_t comes from the cstddef header. Can you please add a #include <cstddef> to each of the files as well?

[xwnb]

It seems reasonable to me. According to https://en.cppreference.com/w/cpp/types/nullptr_t, nullptr_t comes from the cstddef header. Can you please add a #include <cstddef> to each of the files as well?

This header is contained by other stardand header, such as #include <utility> or #include <variant>. I think we don't have to add this extra header.

[clalancette]

This header is contained by other stardand header, such as #include <utility> or #include <variant>. I think we don't have to add this extra header.

While that is true, I always like to include what I'm using. You never know when a downstream header will change. So please add it in.

[clalancette]

Can you please sign your second commit? That will allow our DCO bot to pass. Once that is done, I can run CI here. Thanks.

[xwnb]

I am trying do push the new commit. But it is a connect fatal. I do not know why. Can you offer me some help?

git push --force-with-lease origin master
Connection reset by 13.250.177.223 port 22
fatal: Could not read from remote repository.

Please make sure you have the correct access rights

[clalancette]

I am trying do push the new commit. But it is a connect fatal. I do not know why. Can you offer me some help?

Hm, I don't know, sorry. I've reset this back to the old commit, then you can try pushing without --force-with-lease to see if it is any better.

[xwnb]

Works. Thanks @clalancette 👍

[clalancette]

CI:

• Linux
• Linux-aarch64
• macOS
• Windows