c++ - constructing enum with underlying "bool" type from a boolean? -

if define enum so:

enum foo : bool { left = false, right = true };

then try construct 1 boolean so:

int main (int ac, const char **av) {     foo foo ( ac > 1 );     cout << boolalpha << bool(foo) << endl;     return 0; }

it fails, works constructor so:

foo foo ( foo( ac > 1 ) );

why this? thought foo foo (...) was explicit constructor call?

i don't think can this:

foo foo ( ac > 1 );

suppose define foo enum as:

enum foo : bool { left = false };

what happen if called:

foo foo(true);

you don't have appropriate enum value want initialize with.

M16