Allow to disable inline namespaces completley

[ingo-loehken]

Description

Inline namespaces do not coexist with C++/CLI. Therefore it would be great, to allow disabling inline namespaces at all.

Discussion from Microsoft Developer Community
https://developercommunity.visualstudio.com/t/ccli-bug-with-inline-namespaces-header/14964

Reproduction steps

Create a project with C++/CLI support and include any nlohmann/json Header.

Expected vs. actual results

No compiler error.

Minimal code example

No response

Error messages

compiler error: cannot reopen non inline namespace as inline

Compiler and operating system

Visual C++ 16.11.18 (Visual Studio 2019)

Library version

3.11.2

Validation

• The bug also occurs if the latest version from the develop branch is used.
• I can successfully compile and run the unit tests.

[nlohmann]

Removing bug label as this is a compiler bug with MSVC. We use several versions in the CI.

[falbrechtskirchinger]

That's already possible.

https://json.nlohmann.me/features/namespace/#disabling-the-inline-namespace-completely

[falbrechtskirchinger]

Removing bug label as this is a compiler bug with MSVC. We use several versions in the CI.

We don't test C++/CLI aka. managed C++. Do we even support non-standard C++ officially?

[nlohmann]

Sorry I missed the C++/CLI part. No, we don't test it (yet - happy to see a PR). And also no, we do not support non-standard C++.

[ingo-loehken]

You are right, redefining the BEGIN and END namespaces macros should be sufficient. I will test that and report back here.

[ingo-loehken]

works as expected. thx.