The iterator library that is part of the C++ Standard Library provides the following helpers for writing generic code:
#include // helpers are defined here
template
void foo(Container& c)
{
// Generic way to obtain (constant) iterators
auto b = std::begin(c); // (1)
auto cb = std::cbegin(c); // (2)
auto e = std::end(c); // (3)
auto ce = std::cend(c); // (4)
…
Since C++11 there are elegant way to access each element of a containers (or, more generally, sequences) – so called range-for-statement. The syntaxes are follow:
template
void foo(Container& container)
{
for (auto element : container); // (1)
for (const auto…
Let’s slightly modify the example from The Move Iterator Adapter in C++ post:
#include
#include
#include
#include
/// @warning BUG! PLEASE, DON'T USE!
auto deep_copy_to_list(const std::vector& src)
{
std::list dst; // constructs the empty list
copy(cbegin(src)…
The dereference prefix operator * being applied to iterator returns the lvalue reference to the element pointed by the iterator. Therefore, algorithms such as std::copy or std::transform calls copying constructors of processed elements, for example:
#include
#include
#include
#include
auto deep_copy_to_list(const std::vector& src)
{
std::list dst(src.size()); // allocate the memory to…
By using bidirectional iterator or random access iterator (see Iterator Categories in C++) it’s possible to traverse the sequence in backward direction by using operator -- or by using the special adapter template class std::reverse_iterator. But why to bother with reverse…
Iterator abstracts the concept of pointer to the sequence in range [begin, end), and thus provides the following basic operations:
dereference to obtain the current element;movement to point the next element;comparison to determine at least the end of…
