[Issue 12655] foldRange

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=12655

--- Comment #3 from jens.k.mueller at gmx.de ---
A cumulate returning the same number elements can be written using map.

auto cumulate(alias f, R, T)(R r, T seed)                                       
    if (isInputRange!R && is(T == ElementType!R))                               
{                                                                               
    import std.algorithm : map;                                                 
    return r.map!(a => a = seed = f(seed, a));                                  
}

I leave this here for reference and others to decide whether such a function
should be added to Phobos.

--