import std.stdio;

struct OpApply {
    int opApply(int delegate(int) cb) {
        return cb(42);
    }
}

struct Bolinha {
    int a;
    this(ref OpApply moviadao) {
        foreach(int b; moviadao) {
            this.a = b;
            return;
        }
    }
};

void main() {
    import std.stdio;

    OpApply range;
    writeln(Bolinha(range).a);
}

The expected print result was 42. But I get a random memory garbage instead. The following minor modification in main will 'fix' the issue:

void main() {
    import std.stdio;

    OpApply range;
    Bolinha littleBall = Bolinha(range);
    writeln(littleBall.a);
}