Compiler errors about mlib

[jacknicklenson]

Okey now i get it why it is not work i have to define :

_Bool cmp(node_s n1, node_s n2) {
  return (n1.w == n2.w && n1.h == n2.h);
}

ARRAY_DEF(arr_node, node_s, (CMP(cmp)))

to know how to compare two custom data. thx anyway :)

[P-p-H-d]

By default, ARRAY_DEF expects to work on integer/float types, whereas a struct is used. Some operations are not possible on structures in C. So, the solution is to give the oplist responsible to handle POD struct to ARRAY_DEF:

ARRAY_DEF(arr_node, node_s, M_POD_OPLIST)

This will use the C function memcmp to compare your structure.
Alternatively, you can also register globally the oplist of your node by defining the macro M_OPL_node_s:

#define M_OPL_node_s() M_POD_OPLIST
ARRAY_DEF(arr_node, node_s)

This generates the same code.

_Bool cmp(node_s n1, node_s n2) {
  return (n1.w == n2.w && n1.h == n2.h);
}
ARRAY_DEF(arr_node, node_s, (CMP(cmp)))

There is an issue with this solution: the provided function is a matching method for the EQUAL operator, not for the CMP operator. The CMP operator expects a total order of the elements, like this:

int cmp(node_s n1, node_s n2) {
  return (n1.w < n2.w ? -1 : n1.w > n2.w ? 1 : n1.h < n2.h ? -1 : n1.h > n2.h);
}
ARRAY_DEF(arr_node, node_s, (CMP(cmp)))

[jacknicklenson]

hmmm very nice explanation,i see right now, thank you very much! :)