I'm working with DSP in code that's a mashup of objective C++ and C.

The CoreAudio framework is providing me buffers of audio sample data as float pointers

e.g. `float *bufferData = (float *)malloc(sizeof(float) * 1024);`

The C function that I'm calling to do processing on the sample data requires a pointer of type **double**.

```
double returnAValue(double *sampleData, int samplecount);

```

What's the most CPU efficient way of converting my float pointer into a double pointer before passing it to this function?