While using proto with some classes that have a templated operator[] on VC8 and VC9, I have run into a '2 overloads have similar conversions' ambiguity error (C2666). The problem seems to be with subscript_wrapper in detail/decltype.hpp, where neither the templated operator[] from the original class nor the fallback 'any operator[](any)' function in subscript_wrapper have priority. Any thoughts on how to tweak subscript_wrapper so that the 'any operator[](any)' function looks like a worse match than the templated operator[] and thus prevents the ambiguity? I attached a small test case that reproduces the problem. Also, for reference, I am using the proto code from the release branch as of a couple days ago (~12 Jan 2009). Thanks, -Dave #include <boost/proto/proto.hpp> using namespace boost; struct Abc { template <typename T> void operator[](T const & t) { } }; template< typename Expr > void evaluate( Expr const & expr ) { proto::default_context ctx; proto::eval(expr, ctx); } int main() { Abc a; evaluate( proto::lit(a) [ 0 ] ); return 0; }