c++ - initiating class as a member of struct -

im trying create struct class member inside:

.h file:

class {  public:   struct result   {   int x;   ugraph g;       <------ class definition  };  result m_tempstructresult;   a:a(void);  void function(); } 

.cpp file

a::a() {  }  void a::function() {  ugraph graph(10);      <---- object has receive value   ...               //manipulations on graph  ...   m_tempstructresult.g = graph; } 

the compilation error is:

error c2512: 'a::result' : no appropriate default constructor available 

so problem guess lack of default constructor, added this:

struct result     {         result::result(int graph_size=0) : g(graph_size){         }          int x;         ugraph g;     }; 

and problem solved.

my question if there way initiate class ugraph g inside constructor of class a? , not inside member struct?

thanks.

yes, use initializer list in constructor of result:

result::result() : g(0)  // have insert integer here {  } 

another way in c++11 give default value inside class:

struct result {     ugraph g = ugraph(10); }; 

for small demonstration, see here.

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edit @othmanbenchekroun, believe understood question:

so here example code, uses aggregate initialization in order initialize members of result (without changing constructor of latter).

struct g {     g(int) {} };  struct result {     int x;     g g;   };  struct {     a() : m_tempstructresult{1, g(1)} {}      result m_tempstructresult; };  int main() {     a{}; } 

another demo here.

this not mean, however, suggest this. rather give result appropriate default constructor. otherwise, might become unusable.