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MQX 4.2.0 _io_write vs const data

Question asked by Rudy Vigneault on Feb 4, 2020
Latest reply on Feb 6, 2020 by Daniel Chen



We are using MQX 4.2.0 and I was quite surprised that _io_write is defined to take a non-const buffer for the data:

extern _mqx_int    _io_write(MQX_FILE_PTR, void *, _mqx_int);


I would have expected the second parameter to be something like const void*, furthermore that it is used in the inline definition of fwrite:

#define  fwrite(ptr,so,no,f) (_io_write(f,ptr,(so)*(no))/(so))


My question is: is it safe to assume that neither fwrite nor _io_write will modify the pointer that is given to them?


Can there be a problem to remove the const (using a cast) of an array we want to write using fwrite?