Defining a class member that has required constructor arguments in C++ -

suppose have class foo constructor has required argument. , further suppose i'd define class bar has member object of type foo:

class foo { private:    int x; public:     foo(int x) : x(x) {}; };  class bar { private:     foo f(5); }; 

compiling give errors (in exact case, g++ gives "error: expected identifier before numeric constant"). one, foo f(5); looks function definition compiler, want f instance of foo initialized value 5. solve issue using pointers:

class foo { private:    int x; public:     foo(int x) : x(x) {}; };  class bar { private:     foo* f; public:     bar() { f = new foo(5); } }; 

but there way around using pointers?

if have c++11 support, can initialize f @ point of declaration, not round parentheses ():

class bar { private:     foo f{5}; // note curly braces }; 

otherwise, need use bar's constructor initialization list.

class bar { public:     bar() : f(5) {} private:     foo f; };