Vs14 fixes

[kepkin]

Well, that's it. Everything you need to make it compile and fully work under MSVC 2015.
I'm afraid Appveyor won't be able to build it, as it required to much resource to build unit.cpp in release mode.

[gregmarr]

C++11 allows unions to have members with non-trivial constructors. VS2015 RC now supports this according to the feature table at http://blogs.msdn.com/b/vcblog/archive/2015/04/29/c-11-14-17-features-in-vs-2015-rc.aspx

When you use types with non-trivial constructors and destructors in the union, you need to do more management of the union to change the active member, manually calling the destructor on the previous active member and placement new on the new active member.

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2544.pdf

[gregmarr]

I know this wasn't first introduced in this commit, but this shouldn't use __basic_json as a typedef. Identifiers that start with two underscores are reserved to the C++ implementation (compiler and standard library). That should be renamed to something else, like basic_json_t.

[nlohmann]

Hi @kepkin, thanks a lot for the PR!

[nlohmann]

Hey @gregmarr, you are right with __basic_json, I changed the name to basic_json_t.

About the union: I applied @kepkin's change to a struct, because I do not understand the details. However, you write

When you use types with non-trivial constructors and destructors in the union, you need to do more management of the union to change the active member, manually calling the destructor on the previous active member and placement new on the new active member.

However, in the code, we never change the active member.

[gregmarr]

If you're fine with it being a struct, that's probably the easiest path. Otherwise you have to be sure to manually construct the objects, and that's probably going to be difficult cross-platform.

[nlohmann]

Hi @kepkin again, I have a question with respect to CMake, msbuild, and Appveyor you may help me with: You reported that Appveyor times out when it tries to compile the unit tests. That is very unfortunate but they offer 100% coverage, it would be nice to at least compile them with MSVC to avoid regressions.

In the CMakeLists.txt file, I added -Od to CMAKE_CXX_FLAGS to switch off optimizations. However, these flags seem to be ignored when cmake --build . --config Release is started (see https://ci.appveyor.com/project/nlohmann/json/build/515).

Do you have an idea how to influence this? Or whether there are different ways to make Appveyor compile the code?

[gregmarr]

http://stackoverflow.com/questions/30416804/cmake-disable-optimization-with-od

[nlohmann]

\o/

https://ci.appveyor.com/project/nlohmann/json/build/517

THANKS A LOT!