change include directives to use double quotes

[LuanVSO]

this will close #1
did this with the following regex substitution + manual pruning of some files.

#include\s?<(\w*|Arduino_AVRSTL\.h|system_configuration\.h|unwind-cxx\.h)>
#include "$1"

after these changes i was successfully able to compile a sketch with the following includes:

#include <Arduino_AVRSTL.h>
#include <array>
#include <iostream>

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[aentinger]

LGTM 👍 Thank you @LuanVSO 🚀

[matthijskooijman]

For future reference, I think this change was needed to ensure that this library always includes its own files, rather than the AVr core files. This is particularly the case for the <new> header, which is defined both by uclibc++ and AVR. See also mike-matera/ArduinoSTL#66 (comment) and mike-matera/ArduinoSTL#56 (comment)

[matthijskooijman]

I also wonder if this is really the right fix. Even with this applied, I'm still seeing compilation errors:

In file included from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/common/util/Callable.h:6:0,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/common/util/Logger.h:4,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/common/tuitkit/Core.h:9,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/Menus.h:3,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/DebugMenus.cpp:1:
/home/matthijs/.arduino15/packages/arduino/hardware/avr/1.8.4/cores/arduino/new:25:10: error: redefinition of 'struct std::nothrow_t'
   struct nothrow_t {};
          ^~~~~~~~~
In file included from /home/matthijs/docs/MKIT/3Devo/FeFirmware/libraries/ArduinoSTL/src/memory:20:0,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/libraries/ArduinoSTL/src/char_traits:22,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/libraries/ArduinoSTL/src/iosfwd:21,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/libraries/ArduinoSTL/src/iterator:21,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/libraries/ArduinoSTL/src/algorithm:19,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/common/tuitkit/Core.h:5,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/Menus.h:3,
                 from /home/matthijs/docs/MKIT/3Devo/FeFirmware/src/DebugMenus.cpp:1:
/home/matthijs/docs/MKIT/3Devo/FeFirmware/libraries/ArduinoSTL/src/new:32:21: note: previous definition of 'struct std::nothrow_t'
  struct _UCXXEXPORT nothrow_t {};

This is with a fairly complex sketch, but I would expect the same thing to happen with a simpler sketch too.

I wonder if it would not be better for this library to simply use the AVR-provided if it is present, or revert to its own version of when the AVR core does not provide it. I thought this could be done by reverting this PR, and appling the second suggestions from mike-matera/ArduinoSTL#56 (comment) to fix the _UCXXEXPORT issue, but that still seems to leave a conflict about std::no_throw being defined twice (previously pointed out here).

More generally, there is more new-related stuff between the AVR core and this library's .cpp files (i.e. it's not just a matter of header conflicts). In practice, it seems it's only the std::nothrow that has an issue, but that's probably because a bunch of other new/delete operators are declared weak in the AVR core, so can be replaced by the uclibc++ implementations. It would make some sense to simply remove all the new-related stuff from this library, but that breaks compatibility with older AVR core versions that did not (completely) define the <new> header yet.

Ideally, you would just sort this using preprocessor directives (are already some checks for ARDUINO < 100 in e.g. new_op.cpp), but there is not currently any way AFAIK to detect the core version number (ARDUINO worked when the AVR core and IDE version were tightly coupled, but is currently completely meaningless, especially since IDE and arduino-cli/arduino-builder versions are unrelated too).

One workaround would be to #include <new> and then check for the include guard defined by new in this library, __STD_NEW_OPERATOR (or alternatively add a more specifically named define specifically for this purpose). This allows detecting whether the AVR core offers <new> or not, and allows this library to omit all new-related stuff if it does (i.e. add guards in all new_*.cpp and del_*.cpp files). I think this should fix the issue completely, except for AVR core 1.8.3, which does expose <new>, but it is incomplete (though it might be sufficient for most sketches if uclibc itself doesn't choke on the missing parts).

I've gone ahead and implemented my suggested approach, which seems to work. I haven't done extensive testing, though, so testing is very welcome. PR is here: #8