c++ - Function overloading vs function variable initialization -

I want to know which codes work better under normal circumstances and if there is any relevant difference between them. .

1 case

  float x; Float echo (float a, float b, float x = x) {// a, b, work with x}}   
 2 case  
  float x; Float foo (float a, float b, float x) {// do stuff with A, B, x ...} float foo (float A, float B) {// do stuff with A, B, x ... }    
 
 
 The default argument is a blessing and a curse; They allow you to reduce the repetition of the controllers - which can cause errors themselves  
 Unfortunately, they also mean that many times more diligence is required when the refactoring code, especially when you have a Only submit more and more forms of finger prints.  
   Few blank (integer count, void * p = nullptr, int count = 1);   
 is happening  
  some are not cracked (integer count, bool hasPtr = true, zero * ptr = nullptr, int count = 1);   
 is causing a problem where people were actually filled in all 3 arguments. SomeFunc (10, p, 0)   is going to match successfully  
  someFunc (/ * count = * / 10, / * hasPtr = * / true, / * ptr * / = null, / * count * / = 1)   
 So remember to fix it There is additional work to do. My experience has been that other programmers often come after this kind of change and there is a rotten situation of dirty crash / behavior.