c++ - GCC and devirtualization inlining -

why, in following code, compiler, knowing exact type, can't inline virtual function?

https://goo.gl/agvefx

using namespace std;  struct base{     void fire(){         show();     }      virtual void show() =0;/*{         cout << "base";     }*/ };  struct : base{     inline __attribute__((__always_inline__)) void show() {         cout << "a";     } };  int main() {     a;   (int i=0;i<1000;i++){     a.fire();   }     //a.fire();      return 0; } 

can this, without crtp?

i'm not @ reading assembler code, way see example, when in main:

1. 1000 loaded register
2. 1 substracted,
3. the address of "a" loaded ,
4. the output operator called before
5. jump beginning of loop.

i don't see call fire or show. keeps implementation show, not used. correct because has external linkage.

if put in anonymous namespace, implementation can omitted.

could put reasoning assembler code in question? reference, here generated assembler code provides link:

.lc0:     .string "a" a::show():     movl    $1, %edx     movl    $.lc0, %esi     movl    std::cout, %edi     jmp std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, long) main:     pushq   %rbx     movl    $1000, %ebx .l3:     movl    $1, %edx     movl    $.lc0, %esi     movl    std::cout, %edi     call    std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, long)     subl    $1, %ebx     jne .l3     xorl    %eax, %eax     popq    %rbx     ret     subq    $8, %rsp     movl    std::__ioinit, %edi     call    std::ios_base::init::init()     movl    $__dso_handle, %edx     movl    std::__ioinit, %esi     movl    std::ios_base::init::~init(), %edi     addq    $8, %rsp     jmp __cxa_atexit