C++: Check values of all object properties in a vector -

i think best explained pseudo-code:

std::vector<yes> objs; //the yes class constructor: yes(x,y) //let's imagine instantiated vector 1 object somewhere appropriately  void insomefunction() {    for(int = 0; < 20; ++i)    {       int randx = rand() % mapwidth;       int randy = rand() % mapheight;        for(int j = 0; j < objs.size(); ++j)       {          if(randx > x + threshold, objects in vector && randy > y + threshold, objects in vector)          {             objs.push_back(yes(randx,randy));          }       }    } } 

so have window, dimensions mapwidth , mapheight , trying make 20 objects not overlap 1 in xy-plane.

i want make sure randx , randy not overlapping threshold distance away other existing objects. let's threshold = 20, want make sure randx , randy not contained circle of radius 20 surrounding any/all existing object(s) in vector.

example clarity: first yes object @ (x,y) = (10,20) , threshold = 20, want create second object, taking randx , randy parameters, , push vector; however, want make sure point (randx,randy) doesn't lie in circle of radius 20 , centered @ (10,20) coordinates of first object. program can either generate random (x,y) or generate randx , randy in way fit conditions want, need keep checking objects in vector create more objects.

i want know how accomplish this? more clarity, it's game. i'm trying generate multiple buildings in 2d map, don't want them overlap or close each other. how go accomplishing this?

i break down smaller functions.
this:

bool overlaps(const yes& thing, int x, int y) {    // see if (x, y) overlaps 'thing' in whichever way appropriate. }  bool overlaps_any(const std::vector<yes>& things, int x, int y) {    (const yes& thing : things)    {       if (overlaps(thing, x, y))       {          return true;       }    }    return false; }  void insomefunction(std::vector<yes>& objs) {    for(int = 0; < 20; ++i)    {       int x = 0;       int y = 0;       {          x = rand() % mapwidth;          y = rand() % mapheight;       } while (overlaps_any(objs, x, y));       objs.push_back(yes(x,y));     } } 

there possibly more efficient ways, since generate map once, wouldn't worry efficiency @ moment.