V8::Number to unsigned int?

[Jeremy Darling]

I'm trying to wrap up some hardware libraries for use with Node.js and have run into a casting issue.  I did some searching around, but Google and the cheat sheets failed me.  Can anyone answer how I should properly convert an argument to a unsigned int?

  Local<Integer> pin = Uint32::New(args[0]->NumberValue());

  Local<Integer> value = Uint32::New(args[1]->NumberValue());

  if(set_pin(pin, value) < 0){

    ThrowException(Exception::TypeError(String::New("Could not set value on port")));

    return scope.Close(Undefined());

  }

Results in:

  CXX(target) Release/obj.target/gpio/src/gpio.o

../src/gpio.cc: In function ‘v8::Handle<v8::Value> Method(const v8::Arguments&)’:

../src/gpio.cc:51:37: error: cannot convert ‘v8::Local<v8::Integer>’ to ‘unsigned int’ for argument ‘1’ to ‘int set_pin(unsigned int, unsigned int)’

I'm no C expert, so any advice greatly appreciated.

 - Jeremy

[Louis Santillan]

The code you want is:

int n = ( int )( args[ idx ]->Int32Value() );

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[Jeremy Darling]

Worked perfectly, thanks greatly!

To view this discussion on the web visit https://groups.google.com/d/msgid/nodejs/CAB9Rao-tO64kZH_bCrDiNqbMmZrj-rF4BtdjhqCjS3SH2Dbz-g%40mail.gmail.com.

[Trevor Norris]

Possibly more appropriately:

uint32_t val = args[0]->Uint32Value();

Or

int64_t val = args[0]->IntegerValue();