How to convert void* to foo* to comply with C++? -

i trying compile code written in c (ndpireader.c program comes ndpi library, hosted here). i'm using qt creator , gcc compiler.

after doing research here , here, notice compiling c code c++ compiler not best idea. didn't answer of how conversion , make code c++ compatible.

when try run code in qt creator error bellow:

error: invalid conversion 'void*' 'ndpi_flow_struct*' [-fpermissive] if((newflow->ndpi_flow = malloc_wrapper(size_flow_struct)) == null) { ^

if more info needed solve problem please leave comment. i'm new c++ detailed answers links appreciated.

edit: here malloc_wrapper() function's code

static void *malloc_wrapper(unsigned long size) {   current_ndpi_memory += size;    if(current_ndpi_memory > max_ndpi_memory)     max_ndpi_memory = current_ndpi_memory;    return malloc(size); } 

you're seeing error because in c++, types should have exact match.

as can see, malloc_wrapper() function returns void * , newflow->ndpi_flow of type ndpi_flow_struct*. while compiling using c++ compiler, you've add cast, like

if((newflow->ndpi_flow=(ndpi_flow_struct*)malloc_wrapper(size_flow_struct)) == null) { . . .  

to force compiler in believing return value of malloc_wrapper() of type (ndpi_flow_struct*).

or better, static cast<> (keeping in mind c++ aspect), like

if(( newflow->ndpi_flow =                  static_cast<ndpi_flow_struct*>malloc_wrapper(size_flow_struct)) == null) { . . . 

related reading: a detailed answer on c++ casting.