V 3.9.1: not all compilers support exceptions

[SDziamchuk]

Hello! I'm use this library in my mbed-os projects. But in last update exceptions was added. And ARM Compiler does not support exceptions:

[Error] json3.9.1.hpp@16457,9: cannot use 'throw' with exceptions disabled
[Error] json3.9.1.hpp@16470,9: cannot use 'throw' with exceptions disabled

ARM Compiler version: 6.14.
Is it possible not to use exceptions for more compatibility with different compilers?

[nlohmann]

Yes, they can be switched off. See

• https://nlohmann.github.io/json/home/exceptions/#switch-off-exceptions
• https://github.com/nlohmann/json#further-notes (last item)

[SDziamchuk]

According to this https://os.mbed.com/docs/mbed-os/v6.4/program-setup/build-profiles-and-rules.html
flag -fno-exceptions is set by default for GCC_ARM.
I added define to my code

#define JSON_THROW_USER(exception)  {std::abort();}
#include "../third_party/nlohmann/json.hpp"

But nothing happened. I got same error.

[nlohmann]

Can you try just defining JSON_NOEXCEPTION?

[SDziamchuk]

Yes, I tried. It does not help.

[gregmarr]

@nlohmann Those two lines do have raw throw calls.

throw std::out_of_range("key not found");

[gregmarr]

Fixed in this PR #2347

[gregmarr]

@SDziamchuk This should be fixed in the latest code.