OVMS3-idf/examples/cxx/exceptions/README.md
Jakob Hasse 31edd48b43 C++: Moved all C++ examples to own folder
* moved C++ examples to a new cxx folder in
  examples
* added experimental C++ component
* added ESPException class to the C++ experimental
  component
* added test cases for ESPException and
  corresponding test macros
2020-02-18 12:48:57 +08:00

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# Example: C++ exception handling
(See the README.md file in the upper level 'examples' directory for more information about examples.)
This example demonstrates usage of C++ exceptions in ESP-IDF.
By default, C++ exceptions support is disabled in ESP-IDF. It can be enabled using `CONFIG_COMPILER_CXX_EXCEPTIONS` configuration option.
In this example, the `sdkconfig.defaults` file sets the `CONFIG_COMPILER_CXX_EXCEPTIONS` option. This enables both compile time support (`-fexceptions` compiler flag) and run-time support for C++ exception handling.
The example source code declares a class which can throw exception from the constructor if the argument provided is equal to `0`. This is used to demonstrate that exceptions can be thrown and caught using standard C++ facilities.
**Note: Due to the use of the C++ exceptions, this example is written in C++ instead of C.**
## How to use example
### Hardware Required
This example should be able to run on any commonly available ESP32 development board.
### Configure the project
```
idf.py menuconfig
```
### Build and Flash
```
idf.py -p PORT flash monitor
```
(Replace PORT with the name of the serial port.)
(To exit the serial monitor, type ``Ctrl-]``.)
See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.
## Example Output
```
app_main starting
In constructor, arg=42
In constructor, arg=0
In destructor, m_arg=42
Exception caught: Exception in constructor
app_main done
```