BOOST_VMD_ASSERT_IS_NUMBER — Asserts that the sequence is a number.
// In header: <boost/vmd/assert_is_number.hpp>
The macro checks that the parameter is a number. If it is not a number, it forces a compiler error.
The macro normally checks for a number 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.
sequence = a possible number.
returns = Normally the macro returns nothing. If the sequence is a number, 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 number 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 number.