lex&yacc8--wehter use in C++

bintree.h:12:1: error: unknown type name ‘using’
 using namespace std;
 ==============

bintree.h:28:1: error: unknown type name ‘class’
 class CBintree

==============

the result is that lex&yacc cannot use in C++, i use flex and yacc and gcc to compile the program