c++ - Why parameter can be passed to constructor by assignment operator at object initialization？ -

class {     a(int b); } main(){     int b=5;     tempa=b; }

how work?

i came across problem in hw?

can help? thanks.

a constructor 1 shown in question called conversion constructor.

it allows compiler take value of argument type , convert instance of class.

in example, line

a = b;

is equal to

a = a(5);

(well, exception of conflict of having both class , variable named a)

if want disallow it, have make constructor explicit

class { public:     explicit a(int); };

then compiler can not use constructor conversions 1 described above. have explicitly use constructor.

MOno