C++11 range-based for loops without loop variable

Question

In C++ I need to iterate a certain number of times, but I don\'t need an iteration variable. For example:

for( int x=0; x<10; ++x ) {
    /* code goes her         


        

Answer 1

There isn't any way to make a range based for work for simply iterating over several numbers.

C++11 range-based loops require a ranged expression which may be:

• an array or
• a class having either
  • Member functions begin() and end() or
  • available free functions begin() and end() (via ADL)

In addition to that: A range based for produces some overhead:

for ( for_range_declaration : expression ) statement

expands to

range_init = (expression)
{
  auto && __range = range_init;
  for ( auto __begin = begin_expr,
  __end = end_expr;
  __begin != __end;
  ++__begin ) {
    for_range_declaration = *__begin;
    statement;
  }
}

Where begin_expr and end_expr are obtained via array inspection or begin() / end() pairs.

I don't think this gets any "cleaner" than a simple for-loop. Especially with respect to performance. No calls, just a plain loop.

The only way I can figure out to make it more elegant (where elegant is clearly subject to my opinion) is by using a size or unsigned type here:

for(size_t x(0U); x<10U; ++x) f();