So.... I thought I had all the expression template stuff pretty much done, and then I tried some real world use cases (compiling all the students_t distribution functions with my extended-precision FP type) and everything fell apart: * VC10 wouldn't compile the code at all - more or less runs the system out of swap space (takes about 10 minutes or more!), then exits with an internal compiler error (if I break the code down into it's parts and instantiate each part separately it does compile though - that's not a solution though!). * GCC-4.4.x fails to compile the code due to clashes between boost::math::complement (a function) and boost::proto::complement (a class). I suspect this is an old gcc bug (finding structures via ADL) - I guess the solution is to not derive my number type from a proto-type so ADL can't find proto:: classes? Or will I hit this from some other unforeseen lookup? * GCC-4.5.0 Fails with an internal compiler error :-( * GCC-4.6.0 Builds the code OK, but takes a long time - though possibly just barely acceptable. I suspect this is a "triple template" problem: * proto is complex template library. * my number class is a fairly large/complex template in it's own right. * the code above gets instantiated from deep within Boost.Math's internals. Other than using proto::switch in the grammar (which I'm doing already), is there anything I can do to reduce the template load on the proto side of things? Otherwise since I'm only using a tiny fraction of proto's capabilities, the only other option I can see is to rip it out and replace with a mini-proto designed to minimalize template instantiations within this particular use case. Thanks in advance, John.