Dear Experts. I am getting "invalid redeclaration of nested class" warnings when I include "bimap/bimap.hpp" and use intel compiler(v12). Actually, these warnings are still present when the source has nothing but the #include and an empty main(). I noticed that I don't get these warnings with gcc (v4.1.2). I tried to debug the warning but I am still not sure whether the compiler (and/or boost settings for it) is beeing extra carefull and the warning is benign. Thank you, Oleksiy 1>boost/bimap/tags/support/tag_of.hpp(57): warning #1170: invalid redeclaration of nested class 1> BOOST_BIMAP_STATIC_ERROR( USING_TAG_OF_WITH_AN_UNTAGGED_TYPE, (Type) ); 1> ^ 1> 1boost/bimap/relation/support/member_with_tag.hpp(73): warning #1170: invalid redeclaration of nested class 1> BOOST_BIMAP_STATIC_ERROR( MEMBER_WITH_TAG_FAILURE, (Relation,Tag) ); 1> ^ 1> 1>boost/bimap/relation/support/value_type_of.hpp(57): warning #1170: invalid redeclaration of nested class 1> BOOST_BIMAP_SYMMETRIC_METADATA_ACCESS_BUILDER 1> ^ 1> 1>boost/bimap/relation/support/pair_type_by.hpp(48): warning #1170: invalid redeclaration of nested class 1> BOOST_BIMAP_SYMMETRIC_METADATA_ACCESS_BUILDER 1> ^ 1>