A RetroSearch Logo

Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Search Query:

Showing content from https://cplusplus.com/reference/map/map/cbegin/ below:

public member function

<map>

std::map::cbegin 
const_iterator cbegin() const noexcept;

Return const_iterator to beginning

Returns a const_iterator pointing to the first element in the container.

A const_iterator is an iterator that points to const content. This iterator can be increased and decreased (unless it is itself also const), just like the iterator returned by map::begin, but it cannot be used to modify the contents it points to, even if the map object is not itself const.

If the container is empty, the returned iterator value shall not be dereferenced.



Parameters none

Return Value A const_iterator to the beginning of the sequence.

Member type const_iterator is a bidirectional iterator type that points to const elements (of type const value_type).


Notice that value_type in map containers is an alias of pair<const key_type, mapped_type>.

Example 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
// map::cbegin/cend
#include <iostream>
#include <map>

int main ()
{
  std::map<char,int> mymap;

  mymap['b'] = 100;
  mymap['a'] = 200;
  mymap['c'] = 300;

  // print content:
  std::cout << "mymap contains:";
  for (auto it = mymap.cbegin(); it != mymap.cend(); ++it)
    std::cout << " [" << (*it).first << ':' << (*it).second << ']';
  std::cout << '\n';

  return 0;
}

Output: 
mymap contains: [a:200] [b:100] [c:300]


Complexity Constant.

Iterator validity No changes.

Data races The container is accessed.
No contained elements are accessed by the call, but the iterator returned can be used to access them. Concurrently accessing or modifying different elements is safe.

Exception safetyNo-throw guarantee: this member function never throws exceptions.
The copy construction or assignment of the returned iterator is also guaranteed to never throw.

See also
map::cend
Return const_iterator to end (public member function)
map::begin
Return iterator to beginning (public member function)
map::crbegin
Return const_reverse_iterator to reverse beginning (public member function)

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4