TITLE: New cast notations adopted for C++

[ Material taken from "C++ Report", Sept. 94, Vol. 6, No. 7,
  page 46. ]


The ANSI/ISO C++ Standards Committee has adopted new cast notations
to be included as part of C++. This is the first installment of a
series detailing the coming language changes.

The ordinary C++ cast syntax is roughly "(T) expr", while the newer
dynamic cast syntax is "dynamic_cast<T>(expr)".

The committee identified two outstanding problems with the original
cast syntax that prompted the effort to expand cast operations:

	1) its minimal syntax makes it hard to see both for humans
	   and code analyzers,

	2) it has a single notation for several weakly related
	   operations, including

		reinterpret bit patterns,
		arithmetic narrowing or widening,
		address arithmetic for navigating class heirarchies,
		remove const or volatile

The committee accepted a proposal that will now define three more
cast notations. All are intended to make the original intent of a
designer clearer and more explicit. The casts and their intended 
uses are:

	1) static_cast: for well-behaved and reasonably well-
	   behaved casts

	2) reinterpret_cast: for casts yielding values that must
	   be cast back in order to be used safely

	3) const_cast: for casting away the const and/or
	   volatile attributes

(to be continued)