struct ComboProps1
{
    enum { width = 200 };
    enum { height = 500 };
    enum { some_bool_prop1 = false };
    ...
};

struct ComboProps2
{
    enum { width = 300 };
    enum { height = 200 };
    enum { some_bool_prop1 = true };
    ...
};

template<typename Props> class TComboBox
{
    enum { width = Props::width };
...
}

TComboBox<ComboProps1> Combo1;
TComboBox<ComboProps2> Combo2;

const int ci = 3; // cv-qualified (initialized as required)
ci = 4;               // ill-formed: attempt to modify const
int i = 2;            // not cv-qualified
const int* cip;   // pointer to const int
cip = &i;            // OK: cv-qualified access path to unqualified
*cip = 4;            // ill-formed: attempt to modify through ptr to const
int* ip;               // cast needed to convert const int* to int*
ip = const_cast<int*>(cip); // defined: *ip points to i, a non-const object     (*1)
*ip = 4;
const int* ciq = new const int (3); // initialized as required
int* iq = const_cast<int*>(ciq);    // cast required
*iq = 4;                            // undefined: modifies a const object      (*2)

typedef struct{
   int i;
   float f;
   char* s;
} Tprops;

//----здесь декларации свойств с экономией писанины
static const Tprops prop1 ={13, 3.14, "Name1"}; // это точно попадает в ROM
static const Tprops prop2 ={16, 2.73, "Name2"}; // это точно попадает в ROM

class Tobj {//-------------
  const Tprops* p;
public:
  Tobj(){}
  Tobj(const Tprops* prop) {p=prop;}
  
// здесь можно пользоваться элементами описания *p.f или p->i
};

Tobj example1=&prop1;
Tobj example2=&prop2;

...