Type conversion Conversion

Arithmetic Conversion)

Integer increase (Integral Promotion)

Pointer Conversion

Convert to bool type

Conversion and enumeration types

Convert to const object

Explicit Conversion

Satic_cast, dynamic_cast, const_cast, and reinterpreter_cast

 

Static_cast:

 Any type conversions implicitly executed by the compiler can be explicitly completed by static_cast.

It is useful to use forced type conversion when a large arithmetic type is assigned to a small type.

Dynamic_cast:

E.g.: Assume that base is a class with at least one virtual function, and the derived class is derived from the base class. if there is a pointer named baseptr pointing to base, it can be forcibly converted to a pointer pointing to derived at runtime like this:

If (derived * derivedptr = dynamic_cast <derived *> (baseptr)

{

// Use derived object to which derivedptr points

}

Else {

// Use the base object to which baseptr points

}

At runtime, if baseptr actually points to the derived object, the conversion is successful, and the derivedptr is initialized to the drived object pointed to by baseptr; otherwise, the conversion result is 0, this means that the derivedptr is set to 0 and the condition in if fails.

Const_cast:

It is used to add or delete the const feature. If you use the const_cast character to perform any other type conversion, compilation errors will occur.

E.g .:

Const char * pc_str;

Char * Pc = string_copy (const_cast <char *> (pc_str ));

Reinterpreter_cast:

It usually provides a lower level of re-interpretation for the bit mode of the operand.

 

Forced conversion of legacy types:

Type (expr); // function-style cast notation

(Type) expr; // C-language-style cast notation.