Hi, I am using OpenInventor and boost 1.29 librariess. Both of them have defined int64_t: typedef __int64 int64_t; During compiling I get some errors: d:\work\projects\medint\dist\include\boost\cstdint.hpp(240) : error C2632: '__int64' followed by '__int64' is illegal d:\work\projects\medint\dist\include\boost\cstdint.hpp(240) : warning C4091: 'typedef ' : ignored on left of '__int64' when no variable is declared d:\work\projects\medint\dist\include\inttypes.h(75) : error C2632: '__int64' followed by '__int64' is illegal d:\work\projects\medint\dist\include\inttypes.h(75) : warning C4091: 'typedef ' : ignored on left of '__int64' when no variable is declared The only solution I found is to add #undef just before define at boost/cstdint.hpp: #undef int64_t typedef __int64 int64_t; But it looks as dirty solution. Maybe it is possilbe to solve this problme in more elegant way? P.S. adding #undef int64_t to boost/config/user.hpp only reduces the count of errors from 10 to 6. -- Sigis