boost static link boost.locale error - c++

Question

#include <boost/locale/encoding.hpp>
int main()
{
const std::string strutf8("你好，世界");
std::wstring wtrutf16 = boost::locale::conv::to_utf<wchar_t>(strutf8, "UTF-8");
return 0;
}
this is my code, i want to use boost.locale lib in my project on centos 7 64 bit system, i compile the boost library using ./bootstrap and ./b2,i works fine except i static link libboost_locale.a,i compile in console using:
g++ -o locale locale.cpp -static -L ~/Downloads/boost_1_57_0/stage/lib -lboost_system -lboost_filesystem -lboost_locale
the gcc shows the error like this:
/root/Downloads/boost_1_57_0/stage/lib/libboost_locale.a(codepage.o)：in fuction ‘boost::locale::conv::impl::uconv_to_utf<wchar_t>::open(char const*, boost::locale::conv::method_type)’：
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0xb0)：undefined reference to ‘ucnv_open_50’未定义的引用
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0xcd)：undefined reference to ‘ucnv_close_50’未定义的引用
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0x146)：undefined reference to ‘UCNV_FROM_U_CALLBACK_STOP_50’
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0x14e)：undefined reference to ‘ucnv_setFromUCallBack_50’
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0x16b)：undefined reference to ‘UCNV_TO_U_CALLBACK_STOP_50’
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0x17b)：undefined reference to ‘ucnv_setToUCallBack_50’
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0x18f)：undefined reference to ‘ucnv_getMaxCharSize_50’
codepage.cpp:(.text._ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE[_ZN5boost6locale4conv4impl12uconv_to_utfIwE4openEPKcNS1_11method_typeE]+0x1a2)：undefined reference to ‘ucnv_close_50’
....
i've no idea what happened, i try to install libiconv.a,but i didn't work.
so, would anynoe tell me how to solve this problem.

Answer 1

The symbol name after "undefined reference" belong to ICU4C.
Look like you choose to use ICU4C when compiled the Boost Locale.
There are two solutions:
Add parameter for linking ICU4C library, please visit How To Use ICU for more detail.
Rebuild Boost Locale, set boost.locale.icu=off