Foreach emulation

See also: http://www.artima.com/cppsource/foreach.html

Utilities:

#include <cxxomfort/cxxo-utils.hpp>
// also via
#include <cxxomfort/library/foreach.hpp>

Cxxomfort implements emulation of C++11's "foreach" or for(item: collection), for systems without C++11.

The interface is provided via the CXXO_FOREACH macro and is used as follows:

deque<int> dq;
// add elements to dq...
// later:
CXXO_FOREACH(int v , dq) { 
 // operate on the elements...
}

This feature allows working with sequences and ranges transparently up to the limits established by the compiler. Currently foreach support in cxxomfort goes as follows:

In C++11 mode onwards, this expands to the native for (itemdecl : collection) and is fully compatible with eg.: ref rvalues. range-for iteration, incurring in no cost.
In C++03 mode in compilers supporting typeof (eg.: GCC 4.x, Clang), this makes use of typeof to implement something similar to for (unspecified_iterator b = begin(collection), e = end(collection) ; b != e ; ++b) if(itemdecl) ....
This has no extra cost but might not be fully compatible with some constructs.
In C++03 mode without typeof support (eg.: MSVC 2008-2010), a type-eraed interface is built using the same base that the original Artima article on foreach emulation provides. This has the cost of one virtual function call per iteration.
In compilers without at least C++03 support (eg.: MSVC 2015, Open Watcom), a type-erased reference system is used based on original, simplified versions of the Artima article. This however works only with lvalues.

See Also