javascript - Passing JS number array to emscripten C++ without reinterpret_cast -

have large number arrays in js want pass c++ processing. imho efficient way let js write directly c++ heap , pass pointer argument within direct call, like:

var size = 4096,     bpe = float64array.bytes_per_element,     buf = module._malloc(size * bpe),     numbers = module.heapf64.subarray(buf / bpe, buf / bpe + size),     i; // populate array , process numbers: parseresult(result, numbers); module.myfunc(buf, size); 

the c++ functions process numbers like:

void origfunc(double *buf, unsigned int size) {   // process data ... } void myfunc(uintptr_t bufaddr, unsigned int size) {   origfunc(reinterpret_cast<double*>(bufaddr), size); } 

that works expected wonder if there chance call origfunc directly javascript rid of myfunc , ugly reinterpret_cast.
when tried bind origfunc via:

emscripten_bindings(test) {   function("origfunc", &origfunc, emscripten::allow_raw_pointers()); } 

... , call directly:

module.origfunc(buf, size); 

i error:
uncaught unboundtypeerror: cannot call origfunc due unbound types: pd

is general restriction of emscripten or there "less dirty" solutions reinterpret_cast work around?

you can use static_cast if you

• specify function takes void * rather uintptr_t;

• don't use emscripten_bindings, use emscripten_keepalive + cwrap / ccall way of communicating js->c++ . reason, emscripten_bindings way resulted in gettypename not defined exception when tried it.

so function looks like:

extern "c" int emscripten_keepalive myfunc(void *bufaddr, unsigned int size) {   origfunc(static_cast<double *>(bufaddr), size);   return 0; } 

which can called javascript by

module.ccall('myfunc', 'number' ['number', 'number'], [buf, size]);