Describes how to identify elements within arrays.
Elements within arrays are identified by their logical position within the array.
Elements can also be accessed by key.
For all of the arrays except: RArray<class T>, RPointerArray<class T> and
any of their specialisations, the key structure is defined independently of
the array itself, using:
a TKeyArrayFix object
for arrays of same length elements.
a TKeyArrayVar object
for arrays of variable length elements.
a TKeyArrayPak object
for arrays of packed (variable length) elements.
Accessing an element by key requires the appropriate TKeyArrayFix, TKeyArrayVar or TKeyArrayPak object to be constructed and passed to the appropriate array class member
function.
For the: RArray<class T>, RPointerArray<class T> arrays,
keys are part of the array itself. These arrays also use the classes: