Typedef class with a specific constructor argument

Question

Typedef class with a specific constructor argument

Let's start with a simple class in C ++:

class aClass {
        bool b;
        aClass(bool x){b=x;} 
};

Is it possible to introduce typedef 2 new types stateTrue and stateFalse so that if I do:

stateTrue variable;

it translates to:

aClass  variable(true);

?

+3

c ++ typedef

UldisK 15 Mar 12 at 11:51

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3 answers

No, because it is an instance, not a type.

You can get:

class stateTrue: public aClass {
public:
    stateTrue() : aClass(true) {}
};

0

Oliver Charlesworth 15 Mar 12 at 11:53

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The closest will be

class stateTrue : // new type needed, not just a new name
  public aClass { // but obviously can be converted to aClass
  public: stateTrue() : aClass(true) { } // Default ctor sets aClass base to true
};

0

MSalters 15 Mar 12 at 11:55

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hmjd · Accepted Answer · 2012-03-15T12:00:23+0000

An alternative to inheritance could be to do aClass

a template

:

template <bool T>
class aClass
{
public:
    bool b;
    aClass(): b(T) {}
};

typedef aClass<true>  stateTrue;
typedef aClass<false> stateFalse;

Typedef class with a specific constructor argument

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