The Member initialized list for a default constructor in a composite class does not call the member object constructor.
#include <iostream>
struct test{
test(){
std::cout << "defualt is called" << std::endl;
}
test(int num){
std::cout <<"parameter is called" << std::endl;
}
};
struct test2{
test a;
test2():a(21){}
};
int main(){
test2 b();
}
Nothing is outputted, but if I change the default constructor in the composite class to a parameterized one then it works as expected
#include <iostream>
struct test{
test(){
std::cout << "defualt is called" << std::endl;
}
test(int num){
std::cout <<"parameter is called" << std::endl;
}
};
struct test2{
test a;
test2(int num):a(21){}
};
int main(){
test2 b(4);
}
output is: parameter is called
test2 b();
is a function declaration, not a variable declaration. It declares a function named b
that takes no arguments and returns a test2
. Either of the following would produce a test2
variable that uses the default constructor:
int main(){
test2 b; // No parentheses at all
}
int main(){
test2 b{}; // Curly braces instead of parentheses
}