http://lists.boost.org/MailArchives/boost/msg71266.php
(boost.devel 2004/09/15~)
In the pre-redmond mailing Walter Brown discusses the possibility of adding these members to standard container classes:
const_iterator cbegin();
const_iterator cend();
const_reverse_iterator crbegin();
const_reverse_iterator crbegin();
The motiviation is that we want to be able to say explicitly "give me a const iterator" without doing ugly casts.
('A`)マジで？ってゆーか，なんで"doing ugly casts"？文脈追えてねー．
＃あーもしかしてそのまんま汎用関数に突っ込む時とか？それなら分かる分かる
↓"doing ugly casts"の例（キャストじゃないけれど）
std::vector<int> v; // ..... std::vector<int>::const_iterator ci; // ..... std::size_t d = std::distance<std::vector<int>::const_iterator>(v.begin(), ci); // うにゃ〜！！ //std::size_t d = std::distance(v.cbegin(), ci); // cbeginがあるとこう書ける
