import std.range, std.traits;

​

Target parse(Target, Source)(ref Source source)

    if (isInputRange!Source && isSomeChar!(ElementType!Source) && !is(Source == enum) &&

        isFloatingPoint!Target && !is(Target == enum))

{

    bool anydigits = false;

        if ( anydigits )

        {

            bool anydigits = true;

        }

    return 3.14;

}

​

template isExactSomeString(T)

{

    enum isExactSomeString = isSomeString!T && !is(T == enum);

}

​

private T toImpl(T, S)(S value)

if (isInputRange!S && isSomeChar!(ElementEncodingType!S) &&

    !isExactSomeString!T && is(typeof(parse!T(value))))

{

    return parse!T(value);

}

​

void main()

{

    string foo = "3.14";

    toImpl!real(foo);

}