c++ - Does std::function() check the type when compiling code in C++11 in VS2010? -

i using std::function() in code c++11 , vs2010. here code.

function<string (string)> myfunc = 3; myfunc(string()); 

it obvious code incorrect ,for myfunc object not initialized properly. myfunc object should valued function<string (string)> object other integer type. , when running code myfunc(string());, std::function object throws bad_function_call() , gets error.

however,what confused me why c++11 not check type during compiling time? strange because lack of type check make programmers mess code incidentally, until running according error line.

so want ask: std::function() check type when compiling code in c++11 in vs2010? if not,is there solution problem?

looks hack in ms's implementation of std::function allow following:

function<string (string)> myfunc = null; 

this piece of code find in ms's implementation of <functional> header:

#if defined(_native_nullptr_supported) \     && !defined(_do_not_use_nullptr_in_stl)     function(int)     {   // construct empty function wrapper null pointer         this->_reset();     } #endif /* defined(_native_nullptr_supported) etc. */ 

so looks constructor enabled conditionally based on level of standard conformance user wants.

however, there no such constructor in c++11 standard library specification (see paragraph 20.8.11.2.1).