Boost precompiled headers problem

I try to precompile Boost headers.

First experiment - with std:: headers. I create file std.hpp:

#include <vector> #include <iostream> // And other std:: headers 

After that:

g++ std.hpp 

Copy std.hpp.gch in /usr/include/c++/4.4.5

And write test program:

#include <std.hpp> int main() { std::cout << "Hello, precompiled world!" << std::endl; return 0; } 

Works fine.

Now try precompile Boost headers.

I create boost.hpp file:

#include <boost/spirit/include/qi.hpp> #include <boost/spirit/include/karma.hpp> 

After that:

g++ boost.hpp 

Copy boost.hpp.gch in /usr/local/include/boost

And write test program:

#include <boost/boost.hpp> int main() { // Some code... return 0; } 

But got error:

main.cpp:2:33: error: /usr/local/include/boost/boost.hpp: No such file or directory. 

Try, for experiment:

#include </usr/local/include/boost/boost.hpp> int main() { // Some code... return 0; } 

Same error.

Try copy boost.hpp.gch in another place - same error.

If I put file boost.hpp in same place - works fine (so there is no problems with path):

ls /usr/local/include/boost | grep boost boost.hpp boost.hpp.gch 

So compiler use boost.hpp header. But why compiler don't see precompiled boost.hpp.gch??