c++ - Initialization of a static const variable -


i bit confused following c++ code: 

#include <iostream>  using namespace std;  void test(const string& str) {     static const char * const c = str.c_str();     cout << c << endl; }  int main(int argc, char* argv[]) {    test("hello");    test("nooo");    return 0; }

since variable c declared static , const, shouldn't initialized once , keep initial value until process completed? according reasoning, expecting following output: 

hello hello

but got: 

hello nooo

can clarify why value of variable c has been modified between 2 function calls though const variable?

your program has undefined behavior.

when pass "hello" test, temporary std::string object created, , string c constructed (which pointer data of string object).

when function call ends, temporary std::string object destroyed, , c becomes dangling pointer. using again undefined behavior.

in case, second temporary std::string object's data has exact same memory address first one, c points data. not guaranteed whatsoever.


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