Convert bytes data from const void *data to double

[xobi]

i received bytes data from some other function to myfunction(const void *data) where pointer data stores the values like {0,0,0,0,0,0,0,40,20,0,0,0,0,0,0}.
I created an array data1 to store the values {40,20,0,0,0,0,0,0} from the above values considering endianess issue i also reversed data1 and used memcpy to copy data1 but having problem when i call myfunction then it has argument data not data1. So anyone know how can i call data1 by calling myfunction.
I want to access just values from {40,20,0,0,0,0,0,0} and convert into a double type value that should give 8.0 .

[weaknessforcats]

The custom inn passing an array to a function is to also pass the number of elements.

If you write in C++, then you use a template for the type to avoid the void*.

If you write in C, then you also have to pass a third argument to represent the type so the function knows how to cast the void* to the correct type. Like, maybe, if the third argument is 1 then the functions casts from void* to int* but if it's 2, then the function casts from void* to double*.

[donbock]

Are you absolutely certain that the program sending the byte stream and the program receiving the byte stream happen to use the same encoding format for double? If you have any doubt at all, then you should specify some particular format for the byte stream and then carefully encode the byte stream in the sending program and decode the byte stream in the receiving program.

Merely casting the byte stream to a double is not reliable in the general case.

A convenient portable format for floating point data is decimal ASCII (that is, 8.0 is encoded by "8.0\n". The necessary encoding and decoding functions are part of the Standard Library.