Dear All, I have recently written some code for fixed point arithmetic which I would be happy to contribute to Boost, if it is considered worthy. Please let me know if this is something that you would use, especially if you would be able to help with testing on platforms other than Linux and other tasks necessary for Boostification. Here's a very quick summary: You declare a fixed-point variable by specifying the number of whole-number bits and the number of fraction bits, e.g. fixed<8,23> x; This has a range of about -256 to +256 with a precision of 1/(2^23), and occupies 32 bits. boost::integer is used to choose an implementation type with sufficient bits. The usual arithmetic operators are implemented with some help from boost::operators, and should have no overhead; note that overflow is not detected (like the built-in integral types). Implicit conversions are provided to and from the built-in integral and floating-point types (well, actually I have only added the ones that I have needed; the others should only need copy&paste). Implicit conversion between fixed types of different sizes is also possible. I'm starting to think that perhaps I should make some of these conversion explicit: I worry that code using this might be doing an "invisible" conversion via a floating point type that I didn't want. Any thoughts about this would be appreciated. Operations between fixed-point values of different sizes are possible, and return a fixed-point value with sufficient bits to store the result. For example: fixed<10,4> a; fixed<15,2> b; fixed<15,4> c; c = a + b; ..except that actually one more bit is needed in the maximum-value case. There are no doubt more opportunities for refinement in this area. You can see the code here: http://svn.chezphil.org/libpbe/trunk/include/fixed.hh Thanks for your attention. Phil.