When is a function try block useful?

Question

I\'m wondering when programmers use function try blocks. When is it useful?

void f(int i)
try
{
   if ( i  < 0 ) 
      throw \"less than zero\";
   std::         


        

Answer 1

Function try block are useful for me in two contexts.

a) To have a catch all clause around main() allowing to write small utilities without having to worry about local error handling:

int main()
try {
    // ...
    return 0;
}
catch (...) {
    // handle errors
    return -1;
}

which is clearly just syntactic sugar for having a try/catch inside main() itself.

b) to handle exceptions thrown by base class constructors:

struct B {
     B() { /*might throw*/ }
};

struct A : B {
     A() 
     try : B() { 
         // ... 
     } 
     catch (...) {
         // handle exceptions thrown from inside A() or by B() 
     } 
};