default constructor value for bool type

Question

Hi alltogether,

I am just wondering, which value the default constructor of bool type returns in C++. For instance writing such a code

int i = int();

guarantees that the variable i will be initiated always with 0.

I guess such an initialization routine is possible as well

bool b = bool();

But unfortunately I could not find anywhere which value such a default bool constructor is defined to return. Is the variable b always initialized with false or true. Can anyone help me?

Thanks in advance

Answer 1

bool is an integral type, and value-intialization should make it zero.

Answer 2

false.

[adding characters 'cause of the limit]

Answer 3

The b is initialized also with zero.

Answer 4

Is the variable b always initialized with false or true?

false

Converting true to an integer type will yield 1, and converting false will yield 0 (4.5/4 and 4.7/4)

A very simple test code

#include<iostream>
int main()
{
  bool b=bool();

  if(!b)
  {
     std::cout<<"b: false";
  }

}

Answer 5

bool behaves 'as if it weer declared':

enum bool {false,true};

It is an integral type, might be casted to int as values 0 and 1 (respectively) and its default value is false.