Re: yield iteration

[Timon Gehr]

Ideally it would look like this:

struct Map(alias fun, R){
    R range;
    mixin YieldInputRange!q{
        for(; !range.empty; range.popFront())
            yield fun(range.front);
    }
    static if(is(typeof(range.save))) @property auto save(){
        return Map!(fun, R)(range.save);
    }
    ...
}

Or as a built-in:

struct Map(alias fun, R){
    R range;
    yield {
        for(; !range.empty; range.popFront())
            yield fun(x);
    }
    static if(is(typeof(range.save))) @property auto save(){
        return Map!(fun, R)(range.save);
    }
    ...
}