It's easy to detect in the debugger. The danger is signed int x; cin>>x; if(x+1<x){return OVERFLOW;} will, in modern optimizing compilers, never return OVERF

It's easy to detect in the debugger. The danger is signed int x; cin>>x; if(x+1<x){return OVERFLOW;} will, in modern optimizing compilers, never return OVERFLOW There were quite a few security holes introduced by the compiler with that. ----- The only problem is to make a standard, one has to define that MAX_INT+1 = 0 or something. Then, whenever one does signed int x; cin>> x; signed int y = x+1; really turns into signed int = 0; if ( x < MAX_INT) y= x+1 else y = 1;