Safer enum casts

[bearophile]

If I have an enum of chars, and I have a variable that contains a generic char, 
I may want to convert the second to an instance of the first one, safely (a 
normal cast is enough to do it unsafely). Is it a good idea to give this 
purpose to to!() (this idea is currently not implemented)?


import std.conv: to;
enum Foo : char { a = 'A', b = 'B' }
void main() {
    Foo r1 = cast(Foo)'A'; // OK
    Foo r2 = cast(Foo)'X'; // error undetected
    Foo r3 = to!Foo('A');  // OK
    Foo r4 = to!Foo('X');  // error detected
}

Bye,
bearophile