Hi Arthur,
If your parameters are constant, then you should put in "T const&" for the parameter type.
If the parameters are being mutated by the function (indicated by the absence of const), then temporaries are supposed to generate an error because mutating a temporary is considered a programming error by the compiler. (There are a few ways to work around this situation, but it takes a little more work on the invocation side of the fence, and involves wrapping the temporary with something that returns a non-const reference to itself.)
HTH, --Eljay
