What does the tilde (~) in macros mean?
On the introduction page of Boost.Preprocessor, an example is given in A.4.1.1 Horizontal Repetition #define TINY_print(z, n, data) data #define TINY_size(z, n, unused) \ template <BOOST_PP_ENUM_PARAMS(n, class T)> \ struct tiny_size< \ BOOST_PP_ENUM_PARAMS(n,T) \ BOOST_PP_COMMA_IF(n) \ BOOST_PP_ENUM( \ BOOST_PP_SUB(TINY_MAX_SIZE,n), TINY_print, none) \ > \ : mpl::int_<n> {}; BOOST_PP_REPEAT(TINY_MAX_SIZE, TINY_size, ~) // Oh! a tilde! #undef … Read more