Struct<NativeEnum, EnumHandler> does not work in switch expression

[kevinresol]

I stumbled across this issue #441 which points to this example code:
https://github.com/HaxeFoundation/hxcpp/blob/8eeeee784cca9a271c023030d56e3f6db426076c/test/native/tests/TestNativeEnum.hx

Equality check ((...:SystemMetricStruct) == OS) in Haxe generates this c++ code, which works ✅ :

cpp::Struct<wxSystemMetric, cpp::EnumHandler> val = // ...
if (::hx::IsInstanceEq( wxSYS_OS, val )) { ... }

Switch case (switch (...:SystemMetricStruct) {case OS: ... }) in Haxe generates this c++ code, which does not work ❌ :

cpp::Struct<wxSystemMetric, cpp::EnumHandler> _hx_switch_0 = // ...
if (  (_hx_switch_0==wxSYS_OS) ) { ... }

Error: ./src/RunTests.cpp:235:34: error: use of overloaded operator '==' is ambiguous (with operand types 'cpp::Struct<wxSystemMetric, cpp::EnumHandler>' and 'wxSYS_OS')
                        if (  (_hx_switch_0==wxSYS_OS) ){

[kevinresol]

In fact, even the IsInstanceEq case doesn't really work because it is comparing a native enum directly with a cpp::Struct.

To make it work the compiler should also generate a c++ cast for the native enum value, i.e.

::hx::IsInstanceEq( (cpp::Struct<wxSystemMetric, cpp::EnumHandler>) wxSYS_OS, val )

The mentioned test file works only because of the extra function wrapping, where the arguments are explicitly typed as cpp::Struct, so any param going into the function will be cast correctly.