How to get the address of the std::vector buffer start most elegantly?

Question

I want to use std::vector for dynamically allocating memory. The scenario is:

int neededLength = computeLength(); // some logic here

// this will allocate t         


        

Answer 1

The reason it looks ugly is because you're at the borderline of nice and clean C++ style code and nice and clean C style code. The C++ code uses iterators, the C code uses pointers and sizes.

You could create some glue to circumvent these problems:

template< typename at_Container, typename at_Function >
void for_container( at_Container& c, at_Function f ) {
    f( &c[0], c.size() );
}

and call it in the client code.

void afunction( int* p, size_t n ) { 
   for( int* p = ap; p != ap+n; ++p ) {
     printf( "%d ", *p );
   }
}

void clientcode() {
   std::vector ints(30,3);
   for_container( ints, afunction );
}