prog.cpp:2:22: error: ‘placeholders’ is not a namespace-name
using namespace std::placeholders;
^
prog.cpp:2:34: error: expected namespace-name before ‘;’ token
using namespace std::placeholders;
^
prog.cpp: In function ‘int main()’:
prog.cpp:5:2: warning: ‘auto’ changes meaning in C++11; please remove it [-Wc++0x-compat]
auto f = _1 + _2;
^
prog.cpp:5:7: error: ‘f’ does not name a type
auto f = _1 + _2;
^
prog.cpp:6:15: error: ‘f’ was not declared in this scope
return f(2, 3);
^