[Boost-users] size_type doubts / integer library..

Integer types in C and C++ are a mess. For example, I have made a library where a task is identified by a unique unsigned integer. The extra information about the tasks is stored in a std::vector. When a new task is created, I use the size() method to get the next id, I assign it to the task and then push_back the (pointer to) task structure into the vector. Now, the task structure has also an "unsigned int id" field. In 64-bit mode, sizeof(unsigned) == 4, sizeof(std::vector::size_type) == 8 I get a warnings about type truncation, and obviously, I don't like them. But I like explicit casts and turning off warnings even less. No, I don't want to tie together size_type and task id type (unsigned int). One reason is "aesthetic", another reason is that I don't want the task id type to be larger than necessary (heck, even a 16-bit type would have been enough), because the task IDs will be copied verbatim into another std::vector<unsigned> for further processing (edge lists of a graph). Doubling the size of an integer type shall have bad effects on CPU caches, and I don't want to do it. What to do? Encapsulate into "get_next_id()" function? Have a custom size() function/macro that just casts the result of vector::size and returns it? == Another example: an external library defines its interfaces with signed integer types, I work with unsigned types (why? to avoid even more warnings when comparing task IDs with vector::size() result, as in assert(task->id < tasks.size()), which are abundant in my code). Again, some warnings are unavoidable. What to do to have "clean" code? == Does anyone know about an integer class that lets the user define the number of bits used for storage, lower allowed bound and upper allowed bound for the range? Like: template class Integer; BITS would be allowed to assume a value only equal to the one of the existing integer types (e.g. 8 for char, 16 for short, etc.), and the class would be constrained to hold values in range [low, high] (inclusive). All operations (+-*/<<>><>) would be compile-time checked to make sense. For example, it would be valid to add Integer<32, 0, 8> with Integer<8, 0, 8> and store into Integer<8, 0, 16> (or Integer<8, 0, 17>) result, but NOT into Integer<8, 0, 8> result. The operations would also be checked at run-time to not overflow. Address-of operator would convert to signed or unsigned underlying integer type, depending on the lower bound. Mixing operations with native integer types would be allowed, provided ranges are respected[*]. And, of course, the library should have a "production mode" where the class would turn off all checks. Does anybody know about such a library? Is a unified numeric tower too much to ask for, at least in the form of a library? How do you deal with these issues? [*] If there's no such library in existence, I might be willing to think about a set of "sane" axioms and checks for automatic conversions. And I have "Hacker's Delight" at home, so I can peek into it and get formulas for deriving bounds of arithmetic operations. And yes, is this even easily implementable within C++ template framework; one has to deal with integer overflow.. What happens in template class blah { const long T = A+B; }; when A+B overflows? Compiler error? Undefined result? Did C++0x do anything to clean up the integer types mess? This is a proposal for extension to the C language: http://www.cert.org/archive/pdf/07tn027.pdf Anything similar available for C++? </rant> Or should I just listen to the devil on my shoulder and turn off the appropriate warnings?