Try returns

build/plugins/wasmPlugin.ts

@@ -328,8 +328,6 @@ const wasmPlugin = ({ production }: WasmLoaderConfig = {}): BunPlugin => {
                         '-I', include,
                     ];
 
-                    const std = args.path.endsWith('.cpp') ? STD_CPP : STD_C;
-
                     const inputObjPath = path.resolve(distDir, inputBasename + '.o');
                     const libCObjDir = path.resolve(distDir, 'lib.c');
                     const libCppObjDir = path.resolve(distDir, 'lib.cpp');
@@ -341,6 +339,8 @@ const wasmPlugin = ({ production }: WasmLoaderConfig = {}): BunPlugin => {
                         Array.fromAsync(libCppGlob.scan()),
                     ]);
 
+                    const std = args.path.endsWith('.cpp') ? STD_CPP : STD_C;
+
                     const [, libCObjs, libCppObjs] = await Promise.all([
                         (async () => {
                             const compilationFlags = [...flags, ...std];

src/games/playground/awoo.cpp

@@ -1,9 +1,11 @@
 #include <cstddef>
+#include <cstdint>
 #include <cstdlib>
 #include <iostream>
 #include <js.h>
 #include <stdlib.h>
 #include <string>
+#include <type_traits>
 #include <utility>
 
 class bit {
@@ -86,6 +88,10 @@ JS_EXPORT void awoo() {
     std::cout << "rand = " << rand() << "\narc4 = " << arc4random() << std::endl; 
 }
 
-JS_EXPORT_AS(something) void anything(void (*cb)()) {
+auto autofunc(auto a) requires std::is_integral_v<decltype(a)> {
-    cb();
+    return a + 1;
 }
+
+JS_EXPORT_AS(something) auto anything(uint8_t (*cb)()) {
+    return autofunc(cb());
+}

src/games/playground/index.tsx

@@ -3,5 +3,8 @@ import awoo from './awoo.cpp';
 export default function main() {
     console.log(awoo)
     awoo.awoo();
-    awoo.something(() => console.log('called'));
+    console.log(awoo.something(() => {
+        console.log('called');
+        return 42;
+    }));
 }