.. Sequences/Classes//string |100

string

Description

string is a |variadic|, bidirectional, extensible |Integral Sequence Wrapper| of characters that supports amortized constant-time insertion and removal of elements at both ends, and linear-time insertion and removal of elements in the middle. The parameters to string are multi-character literals, giving a somewhat readable syntax for compile-time strings. string can also be an argument to the c_str metafunction, which generates a null-terminated character array that facilitates interoperability with runtime string processing routines.

__ Bidirectional Sequence_ __ Extensible Sequence_

Header

+-------------------+-------------------------------------------------------+ | Sequence form | Header | +===================+=======================================================+ | Variadic | #include <boost/mpl/string.hpp> | +-------------------+-------------------------------------------------------+

Model of

• |Integral Sequence Wrapper|
• |Variadic Sequence|
• |Bidirectional Sequence|
• |Extensible Sequence|
• |Back Extensible Sequence|
• |Front Extensible Sequence|

Expression semantics

In the following table, s is an instance of string, pos and last are iterators into s, r is a |Forward Sequence| of characters, n and x are |Integral Constant|\ s, and |c1...cn| are arbitrary (multi-)characters.

+---------------------------------------+-----------------------------------------------------------+ | Expression | Semantics | +=======================================+===========================================================+ | .. parsed-literal:: | string of characters |c1...cn|; see | | | |Variadic Sequence|. | | string<|c1...cn|> | | +---------------------------------------+-----------------------------------------------------------+ | .. parsed-literal:: | Identical to string<\ |c1...cn|\ >; | | | see |Variadic Sequence|. | | string<|c1...cn|>::type | | +---------------------------------------+-----------------------------------------------------------+ | begin<s>::type | An iterator pointing to the beginning of s; | | | see |Bidirectional Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | end<s>::type | An iterator pointing to the end of s; | | | see |Bidirectional Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | size<s>::type | The size of s; see |Bidirectional Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | empty<s>::type | |true if and only if| the sequence is empty; | | | see |Bidirectional Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | front<s>::type | The first element in s; see | | | |Bidirectional Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | back<s>::type | The last element in s; see | | | |Bidirectional Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | insert<s,pos,x>::type | A new string of following elements: | | | [begin<s>::type, pos), x, | | | [pos, end<s>::type); see |Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | insert_range<s,pos,r>::type | A new string of following elements: | | | [begin<s>::type, pos), | | | [begin<r>::type, end<r>::type) | | | [pos, end<s>::type); see |Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | erase<s,pos>::type | A new string of following elements: | | | [begin<s>::type, pos), | | | [next<pos>::type, end<s>::type); see | | | |Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | erase<s,pos,last>::type | A new string of following elements: | | | [begin<s>::type, pos), | | | [last, end<s>::type); see |Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | clear<s>::type | An empty string; see |Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | push_back<s,x>::type | A new string of following elements: | | | |begin/end<s>|, x; | | | see |Back Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | pop_back<s>::type | A new string of following elements: | | | [begin<s>::type, prior< end<s>::type >::type); | | | see |Back Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | push_front<s,x>::type | A new string of following elements: | | | |begin/end<s>|, x; see |Front Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | pop_front<s>::type | A new string of following elements: | | | [next< begin<s>::type >::type, end<s>::type); | | | see |Front Extensible Sequence|. | +---------------------------------------+-----------------------------------------------------------+ | c_str<s>::value | A null-terminated byte string such that | | | c_str<s>::value[\ n\ ] is equal to the n\ -th | | | character in s, and | | | c_str<s>::value[size<s>::type::value] is '\0'. | +---------------------------------------+-----------------------------------------------------------+

Example

.. parsed-literal::

typedef mpl::string<'hell','o wo','rld'> hello;
typedef mpl::push_back<hello, mpl::char_<'!'> >::type hello2;

BOOST_ASSERT(0 == std::strcmp(mpl::c_str<hello2>::value, "hello world!"));

See also

|Sequences|, |Variadic Sequence|, |Bidirectional Sequence|, |Extensible Sequence|, |Integral Sequence Wrapper|, |char_|, |c_str|

.. copyright:: Copyright 2009 Eric Niebler Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)