c++ - Index exception in 2D -

I have a problem with the following. I have a square and a square of the entire matrix for a line of matrix applied matrix. I have created rows to reach out to members like that matrix [A] [b] But the problem is with throwing exceptions, which should be in the format "Illegal index [E] [F]". I use the try-hold in the matrix overload [] and can throw the integer exceptions from the overload [] to the lines, but if the first case is correct, the second case will not solve and the other is wrong.

  // matrix overload line & amp; Operator [] (unsigned inx) {return * rows [inx]; } // line overload double & amp; Operator [] (unsigned inx) {return item [inx]; }    
 
 
 
 should be in the exception format such as "invalid index [e] [ F] "  
 It seems very difficult to compare it!  
  If  [f]  is invalid, the  matrix :: operator [] (e)  has already ended that parameter is now available is not.   
 So you have to pass this information in a  line  question at some point. here is a tip.  
  // (member variable "int roe :: index" has been added ...) // matrix overload line & amp; Operator [] (unsigned inx) {rows [inks] - & gt; Setro Index (Inx); Return * rows [inx]; } // line overload double & amp; Operator [] (unsigned inx) {// You can now throw information about both inks and stored row index return items [inx]; }   
  If  [E]  is invalid,  line :: operator [] (f)  is not asked Till now. This is an unknown value.   
 This means that whenever  [E]  is invalid, then it should return something that can  operator []  Still called before throwing.  
  // (member variable "bool row :: isInvalid" has been added ...) // Matrix overload line & amp; Operator [] (unsigned inx) {row * result; If (inx is invalid) {// do not throw it yet! Stable rome dummy; Dummy.setInvalid (); Result = and dummy; } And {result = rows [inx]; } Results-> Setro index (inx); Return * results; } // line overload double & amp; Operator [] (unsigned inx) {// if-> If there is untrue truth, then the first index was bad. // If the inx is invalid, then the second index was bad. // Anyhow, we now have both indexes and can throw! Return items [inx]; }