Can (a==1)&&(a==2)&&(a==3) evaluate to true? (and can it be useful?)

Question

Inspired by another question regarding java-script language. Can the expression

 (a==1)&&(a==2)&&(a==3)

evaluate to true i

Answer 1

Could be somewhat useful.

#include 
#include 
#include 
using namespace std;

struct Foo {
    std::vector v = {1,2,3};
};

bool operator==(const Foo& foo, int i) {
    return std::any_of(foo.v.begin(), foo.v.end(), [=](int v){ return v == i; });
}

int main() {
    Foo a;

    if (a==1 && a==2 && a==3)
        cout << "Really??" << endl;
    return 0;
}