zipfor
======

for-each constructs for C++11 that provide iteration over multiple
containers at the same time (zipping, or parallel iteration -- not
parallel computation)

primarily provides zipfor:
--------------------------
can be used as

vector<int> a {1,2,3};
array<string,3> b {"hello","there","coders"};

zipfor(i,s eachin a,b)
	cout << i << " => " << s;


also provides mapfor:
---------------------

map<int,string> m{{1,"hello"},{2,"there"},{-3,"stranger"}};

mapfor(i,s eachin m) 
	cout << i << " => " << s;



finally, provides ittcounter<T>:
--------------------------------
This is a simple container that counter from 0, by 1s

ittcounter<int>() or ittcounter<float>() or ittcounter<size_t>()

icounter is the same as ittcounter<int>()

can be used like:

map<char,string> m{{'a',"apple"},{'b',"ball"},{'c',"chair"}};
zipfor(v,i eachin m,icounter)
	cout << i << ": " << v.first << " => " << v.second << endl;

icounter (or ittcounter) should *not* be the first member in list
	(or the loop will run for a very long time)

Notes:
-----

o This is a header-only "library" so no compilation is necessary.
o It depends heavily on C++11 (it will not work with C++03 or earlier)
o It has been tested on g++4.8.1 but nothing else at this point (Jun 2014)
o It was briefly tested on g++9.3.1 to fix a bug (Apr 2020)
o It *does* use macros to provide the syntax sugar.
o Any bug reports would be appreciated.

-Christian