C++ shared libraries have duplicate symbols

I am new to c++ symbol tables and libraries, wanted to understand the behavior of symbol table. We are having an android application with native support on it. In process of analyzing symbol tables of shared libraries, I am noticing duplicate symbols present in .so file. Please find the sample list of symbol table.

0162502c  w   DO .data  00000004  Base        boost::asio::error::get_addrinfo_category()::instance

00aaa4f4  w   DF .text  0000009c  Base        boost::asio::error::get_misc_category()

01626334  w   DO .bss   00000004  Base        guard variable for boost::asio::error::get_misc_category()::instance

00aab4d0  w   DF .text  0000003c  Base        boost::asio::error::detail::misc_category::~misc_category()

00aab368  w   DF .text  0000003c  Base        boost::asio::error::detail::addrinfo_category::~addrinfo_category()

00aab3a4  w   DF .text  00000034  Base        boost::asio::error::detail::addrinfo_category::name() const

00aab3d8  w   DF .text  000000f8  Base        boost::asio::error::detail::addrinfo_category::message(int) const

00aab50c  w   DF .text  0000003c  Base        boost::asio::error::detail::misc_category::~misc_category()

Here you can notice following symbol "boost::asio::error::detail::misc_category::~misc_category()" appearing twice.

I wanted to understand why are we getting duplicate symbols in symbol table. Also interested to know why my app is running fine when there are duplicate symbols [ which linker should ideally throw duplicate symbols error ] Also would like to know does having duplicate symbols in symbol tables would increase the size of "so" eventually leading to increasing in the size of app

If this happens, how could I ensure that I get only unique entries in symbol table. Note:- we are using clang