m_bValid for the compiler to find m_bValid

sorry for the long code..
aye i'll try that

long code didn't really make a difference for that, I just looked at the first error and that line, and there seemed to be that problem. Same problem further down, but you get the idea. If there are other problems, I know not

i got optional.h:41: error: declaration does not declare anything
maybe i didn't really understand ur suggestion

line 41? Is that line 43 in the paste, which now should be optional(T const & t) { construct(t); m_typename optional_basesizeof(T)