'multiply defined symbols' when including <boost/filesystem.hpp> in different source files

[anonymous]

When <boost/filesystem.hpp> is included in different source files, the linker complains about 'multiply defined symbols'

Attached: two source files that reproduce the error when compiled and linked in the same project.

boost-1.34.0 MSVC 7.0

test2.obj : error LNK2005: "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl boost::filesystem::extension(class boost::filesystem::basic_path<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::filesystem::path_traits> const &)" (?extension@filesystem@boost@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ABV?$basic_path@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@Upath_traits@filesystem@boost@@@12@@Z) already defined in test.obj
test2.obj : error LNK2005: "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl boost::filesystem::basename(class boost::filesystem::basic_path<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >,struct boost::filesystem::path_traits> const &)" (?basename@filesystem@boost@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@ABV?$basic_path@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@Upath_traits@filesystem@boost@@@12@@Z) already defined in test.obj
Release/test.exe : fatal error LNK1169: one or more multiply defined symbols found

[anonymous]

first file

[anonymous]

second file

[anonymous]

Workaround (works for MSVC 7.0):

add "/force:multiple" to advanced linker options

[frederic.bron@…]

There is an "inline" missing in filesystem/convenience.hpp

# define BOOST_FS_FUNC_STRING std::string

should be

# define BOOST_FS_FUNC_STRING inline std::string

[mkl]

Oh, the fix didn't make it into 1_34_1 :(

[Benjamin Eikel]

This problem exists with mingw/gcc too. But the suggested workaround works.

[Benjamin Eikel]

This problem exists with mingw/gcc too. But the suggestes workaround works.

[Beman Dawes]

(In [38567]) Fix #995 by adding inline