Description

The macro checks that the sequence is a Boost PP array. If it is not a Boost PP array, it forces a compiler error.

The macro normally checks for a Boost PP array only in debug mode. However an end-user can force the macro to check or not check by defining the macro BOOST_VMD_ASSERT_DATA to 1 or 0 respectively.

d = The next available BOOST_PP_WHILE iteration. sequence = a possible Boost PP sequence.

returns = Normally the macro returns nothing. If the sequence is a Boost PP array, nothing is output. For VC++, because there is no sure way of forcing a compiler error from within a macro without producing output, if the sequence is not a Boost PP array the macro forces a compiler error by outputting invalid C++. For all other compilers a compiler error is forced without producing output if the sequence is not a Boost PP array.