# Parallel Iteration

Types `const_range_type` and `range_type` model the Container Range concept. The types differ only in that the bounds for a `const_range_type` are of type `const_iterator`, whereas the bounds for a `range_type` are of type iterator.

The following table provides additional information on the members of this template class.
Member | Description
--- | ---
const_range_type range( size_t grainsize=1 ) const | Returns: A `const_range_type` representing all elements in `*this`. The parameter `grainsize` is in units of elements.
range_type range( size_t grainsize=1 ) | Returns: A `range_type` representing all elements in `*this`. The parameter `grainsize` is in units of elements.

Parent topic: enumerable_thread_specific Template Class