feat: add enum support

Signed-off-by: Gordon Smith <GordonJSmith@gmail.com>

Author: GordonSmith

README.md

@@ -42,7 +42,7 @@ This repository contains a C++ ABI implementation of the WebAssembly Component M
 - [x] Record
 - [x] Tuple
 - [x] Variant
-- [ ] Enum
+- [x] Enum
 - [x] Option
 - [x] Result
 - [x] Flags

include/cmcpp/traits.hpp

@@ -714,6 +714,10 @@ namespace cmcpp
     template <Field Ok, Field Err>
     using result_t = variant_t<Ok, Err>;
 
+    //  Enum  --------------------------------------------------------------------
+    template <typename T>
+    using enum_t = uint32_t;
+
     //  Func  --------------------------------------------------------------------
     constexpr uint MAX_FLAT_PARAMS = 16;
     constexpr uint MAX_FLAT_RESULTS = 1;

samples/wamr/main.cpp

@@ -265,6 +265,18 @@ int main()
     auto call_list_filter_result = call_list_filter({{false}, {"Hello World!"}, {"Another String"}, {true}, {false}});
     std::cout << "call_list_filter result: " << call_list_filter_result.size() << std::endl;
 
+    enum e
+    {
+        a,
+        b,
+        c
+    };
+
+    auto enum_func = attach<enum_t<e>(enum_t<e>)>(module_inst, exec_env, liftLowerContext, "example:sample/enums#enum-func");
+    std::cout << "enum_func(e::a): " << enum_func(e::a) << std::endl;
+    std::cout << "enum_func(e::b): " << enum_func(e::b) << std::endl;
+    std::cout << "enum_func(e::c): " << enum_func(e::c) << std::endl;
+
     wasm_runtime_destroy_exec_env(exec_env);
     wasm_runtime_deinstantiate(module_inst);
     wasm_runtime_unload(module);

samples/wasm/main.cpp

@@ -98,3 +98,8 @@ void exports_example_sample_variants_variant_func(exports_example_sample_variant
         a->val.u = a->val.u * 2;
     }
 }
+
+exports_example_sample_enums_e_t exports_example_sample_enums_enum_func(exports_example_sample_enums_e_t a)
+{
+    return a;
+}

samples/wasm/sample.wit

@@ -40,13 +40,23 @@ interface variants {
   variant-func: func(a: v) -> v;
 }
 
+interface enums {
+  enum e {
+    a,
+    b,
+    c
+  }
+  enum-func: func(a: e) -> e;
+}
+
 world sample {
   export booleans;
   export floats;
   export strings;
   export tuples;
   export lists;
   export variants;
+  export enums;
 
   export void-func: func();
   export ok-func: func(a:u32, b:u32) -> result<u32, string>;