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| author | sanine <sanine.not@pm.me> | 2022-04-16 11:55:54 -0500 |
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| committer | sanine <sanine.not@pm.me> | 2022-04-16 11:55:54 -0500 |
| commit | 8fb7916a0d0cb007a4c3a4e6a31af58765268ca3 (patch) | |
| tree | 52b5524a94a5b04e17a1fd7f8aca988ab6d0c75f /src/mesh/assimp-master/contrib/utf8cpp/doc/utf8cpp.html | |
| parent | db81b925d776103326128bf629cbdda576a223e7 (diff) | |
delete src/mesh/assimp-master
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diff --git a/src/mesh/assimp-master/contrib/utf8cpp/doc/utf8cpp.html b/src/mesh/assimp-master/contrib/utf8cpp/doc/utf8cpp.html deleted file mode 100644 index 6f2aacb..0000000 --- a/src/mesh/assimp-master/contrib/utf8cpp/doc/utf8cpp.html +++ /dev/null @@ -1,1789 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<html> - <head> - <meta name="generator" content= - "HTML Tidy for Linux/x86 (vers 1st November 2002), see www.w3.org"> - <meta name="description" content= - "A simple, portable and lightweigt C++ library for easy handling of UTF-8 encoded strings"> - <meta name="keywords" content="UTF-8 C++ portable utf8 unicode generic templates"> - <meta name="author" content="Nemanja Trifunovic"> - <title> - UTF8-CPP: UTF-8 with C++ in a Portable Way - </title> - <style type="text/css"> - <!-- - span.return_value { - color: brown; - } - span.keyword { - color: blue; - } - span.preprocessor { - color: navy; - } - span.literal { - color: olive; - } - span.comment { - color: green; - } - code { - font-weight: bold; - } - ul.toc { - list-style-type: none; - } - p.version { - font-size: small; - font-style: italic; - } - --> - </style> - </head> - <body> - <h1> - UTF8-CPP: UTF-8 with C++ in a Portable Way - </h1> - <p> - <a href="https://sourceforge.net/projects/utfcpp">The Sourceforge project page</a> - </p> - <div id="toc"> - <h2> - Table of Contents - </h2> - <ul class="toc"> - <li> - <a href="#introduction">Introduction</a> - </li> - <li> - <a href="#examples">Examples of Use</a> - <ul class="toc"> - <li> - <a href=#introsample>Introductionary Sample </a> - </li> - <li> - <a href=#validfile>Checking if a file contains valid UTF-8 text</a> - </li> - <li> - <a href=#fixinvalid>Ensure that a string contains valid UTF-8 text</a> - </li> - </ul> - <li> - <a href="#reference">Reference</a> - <ul class="toc"> - <li> - <a href="#funutf8">Functions From utf8 Namespace </a> - </li> - <li> - <a href="#typesutf8">Types From utf8 Namespace </a> - </li> - <li> - <a href="#fununchecked">Functions From utf8::unchecked Namespace </a> - </li> - <li> - <a href="#typesunchecked">Types From utf8::unchecked Namespace </a> - </li> - </ul> - </li> - <li> - <a href="#points">Points of Interest</a> - </li> - <li> - <a href="#links">Links</a> - </li> - </ul> - </div> - <h2 id="introduction"> - Introduction - </h2> - <p> - Many C++ developers miss an easy and portable way of handling Unicode encoded - strings. The original C++ Standard (known as C++98 or C++03) is Unicode agnostic. - C++11 provides some support for Unicode on core language and library level: - u8, u, and U character and string literals, char16_t and char32_t character types, - u16string and u32string library classes, and codecvt support for conversions - between Unicode encoding forms. - In the meantime, developers use third party libraries like ICU, OS specific capabilities, or simply - roll out their own solutions. - </p> - <p> - In order to easily handle UTF-8 encoded Unicode strings, I came up with a small - generic library. For anybody used to work with STL algorithms and iterators, it should be - easy and natural to use. The code is freely available for any purpose - check out - the license at the beginning of the utf8.h file. If you run into - bugs or performance issues, please let me know and I'll do my best to address them. - </p> - <p> - The purpose of this article is not to offer an introduction to Unicode in general, - and UTF-8 in particular. If you are not familiar with Unicode, be sure to check out - <a href="http://www.unicode.org/">Unicode Home Page</a> or some other source of - information for Unicode. Also, it is not my aim to advocate the use of UTF-8 - encoded strings in C++ programs; if you want to handle UTF-8 encoded strings from - C++, I am sure you have good reasons for it. - </p> - <h2 id="examples"> - Examples of use - </h2> - <h3 id="introsample"> - Introductionary Sample - </h3> - <p> - To illustrate the use of the library, let's start with a small but complete program - that opens a file containing UTF-8 encoded text, reads it line by line, checks each line - for invalid UTF-8 byte sequences, and converts it to UTF-16 encoding and back to UTF-8: - </p> -<pre> -<span class="preprocessor">#include <fstream></span> -<span class="preprocessor">#include <iostream></span> -<span class="preprocessor">#include <string></span> -<span class="preprocessor">#include <vector></span> -<span class="preprocessor">#include "utf8.h"</span> -<span class="keyword">using namespace</span> std; -<span class="keyword">int</span> main(<span class="keyword">int</span> argc, <span class="keyword">char</span>** argv) -{ - <span class="keyword">if</span> (argc != <span class="literal">2</span>) { - cout << <span class="literal">"\nUsage: docsample filename\n"</span>; - <span class="keyword">return</span> <span class="literal">0</span>; - } - - <span class="keyword">const char</span>* test_file_path = argv[1]; - <span class="comment">// Open the test file (contains UTF-8 encoded text)</span> - ifstream fs8(test_file_path); - <span class="keyword">if</span> (!fs8.is_open()) { - cout << <span class= -"literal">"Could not open "</span> << test_file_path << endl; - <span class="keyword">return</span> <span class="literal">0</span>; - } - - <span class="keyword">unsigned</span> line_count = <span class="literal">1</span>; - string line; - <span class="comment">// Play with all the lines in the file</span> - <span class="keyword">while</span> (getline(fs8, line)) { - <span class="comment">// check for invalid utf-8 (for a simple yes/no check, there is also utf8::is_valid function)</span> - string::iterator end_it = utf8::find_invalid(line.begin(), line.end()); - <span class="keyword">if</span> (end_it != line.end()) { - cout << <span class= -"literal">"Invalid UTF-8 encoding detected at line "</span> << line_count << <span - class="literal">"\n"</span>; - cout << <span class= -"literal">"This part is fine: "</span> << string(line.begin(), end_it) << <span - class="literal">"\n"</span>; - } - - <span class="comment">// Get the line length (at least for the valid part)</span> - <span class="keyword">int</span> length = utf8::distance(line.begin(), end_it); - cout << <span class= -"literal">"Length of line "</span> << line_count << <span class= -"literal">" is "</span> << length << <span class="literal">"\n"</span>; - - <span class="comment">// Convert it to utf-16</span> - vector<unsigned short> utf16line; - utf8::utf8to16(line.begin(), end_it, back_inserter(utf16line)); - - <span class="comment">// And back to utf-8</span> - string utf8line; - utf8::utf16to8(utf16line.begin(), utf16line.end(), back_inserter(utf8line)); - - <span class="comment">// Confirm that the conversion went OK:</span> - <span class="keyword">if</span> (utf8line != string(line.begin(), end_it)) - cout << <span class= -"literal">"Error in UTF-16 conversion at line: "</span> << line_count << <span - class="literal">"\n"</span>; - - line_count++; - } - <span class="keyword">return</span> <span class="literal">0</span>; -} -</pre> - <p> - In the previous code sample, for each line we performed - a detection of invalid UTF-8 sequences with <code>find_invalid</code>; the number - of characters (more precisely - the number of Unicode code points, including the end - of line and even BOM if there is one) in each line was - determined with a use of <code>utf8::distance</code>; finally, we have converted - each line to UTF-16 encoding with <code>utf8to16</code> and back to UTF-8 with - <code>utf16to8</code>. - </p> - <h3 id="validfile">Checking if a file contains valid UTF-8 text</h3> -<p> -Here is a function that checks whether the content of a file is valid UTF-8 encoded text without -reading the content into the memory: -</p> -<pre> -<span class="keyword">bool</span> valid_utf8_file(i<span class="keyword">const char</span>* file_name) -{ - ifstream ifs(file_name); - <span class="keyword">if</span> (!ifs) - <span class="keyword">return false</span>; <span class="comment">// even better, throw here</span> - - istreambuf_iterator<<span class="keyword">char</span>> it(ifs.rdbuf()); - istreambuf_iterator<<span class="keyword">char</span>> eos; - - <span class="keyword">return</span> utf8::is_valid(it, eos); -} -</pre> -<p> -Because the function <code>utf8::is_valid()</code> works with input iterators, we were able -to pass an <code>istreambuf_iterator</code> to it and read the content of the file directly -without loading it to the memory first.</p> -<p> -Note that other functions that take input iterator arguments can be used in a similar way. For -instance, to read the content of a UTF-8 encoded text file and convert the text to UTF-16, just -do something like: -</p> -<pre> - utf8::utf8to16(it, eos, back_inserter(u16string)); -</pre> - <h3 id="fixinvalid">Ensure that a string contains valid UTF-8 text</h3> -<p> -If we have some text that "probably" contains UTF-8 encoded text and we want to -replace any invalid UTF-8 sequence with a replacement character, something like -the following function may be used: -</p> -<pre> -<span class="keyword">void</span> fix_utf8_string(std::string& str) -{ - std::string temp; - utf8::replace_invalid(str.begin(), str.end(), back_inserter(temp)); - str = temp; -} -</pre> -<p>The function will replace any invalid UTF-8 sequence with a Unicode replacement character. -There is an overloaded function that enables the caller to supply their own replacement character. -</p> - <h2 id="reference"> - Reference - </h2> - <h3 id="funutf8"> - Functions From utf8 Namespace - </h3> - <h4> - utf8::append - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Encodes a 32 bit code point as a UTF-8 sequence of octets and appends the sequence - to a UTF-8 string. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -octet_iterator append(uint32_t cp, octet_iterator result); - -</pre> - <p> - <code>octet_iterator</code>: an output iterator.<br> - <code>cp</code>: a 32 bit integer representing a code point to append to the - sequence.<br> - <code>result</code>: an output iterator to the place in the sequence where to - append the code point.<br> - <span class="return_value">Return value</span>: an iterator pointing to the place - after the newly appended sequence. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">unsigned char</span> u[<span class="literal">5</span>] = {<span -class="literal">0</span>,<span class="literal">0</span>,<span class= -"literal">0</span>,<span class="literal">0</span>,<span class="literal">0</span>}; -<span class="keyword">unsigned char</span>* end = append(<span class= -"literal">0x0448</span>, u); -assert (u[<span class="literal">0</span>] == <span class= -"literal">0xd1</span> && u[<span class="literal">1</span>] == <span class= -"literal">0x88</span> && u[<span class="literal">2</span>] == <span class= -"literal">0</span> && u[<span class="literal">3</span>] == <span class= -"literal">0</span> && u[<span class="literal">4</span>] == <span class= -"literal">0</span>); -</pre> - <p> - Note that <code>append</code> does not allocate any memory - it is the burden of - the caller to make sure there is enough memory allocated for the operation. To make - things more interesting, <code>append</code> can add anywhere between 1 and 4 - octets to the sequence. In practice, you would most often want to use - <code>std::back_inserter</code> to ensure that the necessary memory is allocated. - </p> - <p> - In case of an invalid code point, a <code>utf8::invalid_code_point</code> exception - is thrown. - </p> - <h4> - utf8::next - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Given the iterator to the beginning of the UTF-8 sequence, it returns the code - point and moves the iterator to the next position. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t next(octet_iterator& it, octet_iterator end); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>it</code>: a reference to an iterator pointing to the beginning of an UTF-8 - encoded code point. After the function returns, it is incremented to point to the - beginning of the next code point.<br> - <code>end</code>: end of the UTF-8 sequence to be processed. If <code>it</code> - gets equal to <code>end</code> during the extraction of a code point, an - <code>utf8::not_enough_room</code> exception is thrown.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - processed UTF-8 code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars; -<span class="keyword">int</span> cp = next(w, twochars + <span class="literal">6</span>); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars + <span class="literal">3</span>); -</pre> - <p> - This function is typically used to iterate through a UTF-8 encoded string. - </p> - <p> - In case of an invalid UTF-8 seqence, a <code>utf8::invalid_utf8</code> exception is - thrown. - </p> - <h4> - utf8::peek_next - </h4> - <p class="version"> - Available in version 2.1 and later. - </p> - <p> - Given the iterator to the beginning of the UTF-8 sequence, it returns the code - point for the following sequence without changing the value of the iterator. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t peek_next(octet_iterator it, octet_iterator end); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>it</code>: an iterator pointing to the beginning of an UTF-8 - encoded code point.<br> - <code>end</code>: end of the UTF-8 sequence to be processed. If <code>it</code> - gets equal to <code>end</code> during the extraction of a code point, an - <code>utf8::not_enough_room</code> exception is thrown.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - processed UTF-8 code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars; -<span class="keyword">int</span> cp = peek_next(w, twochars + <span class="literal">6</span>); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars); -</pre> - <p> - In case of an invalid UTF-8 seqence, a <code>utf8::invalid_utf8</code> exception is - thrown. - </p> - <h4> - utf8::prior - </h4> - <p class="version"> - Available in version 1.02 and later. - </p> - <p> - Given a reference to an iterator pointing to an octet in a UTF-8 sequence, it - decreases the iterator until it hits the beginning of the previous UTF-8 encoded - code point and returns the 32 bits representation of the code point. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t prior(octet_iterator& it, octet_iterator start); - -</pre> - <p> - <code>octet_iterator</code>: a bidirectional iterator.<br> - <code>it</code>: a reference pointing to an octet within a UTF-8 encoded string. - After the function returns, it is decremented to point to the beginning of the - previous code point.<br> - <code>start</code>: an iterator to the beginning of the sequence where the search - for the beginning of a code point is performed. It is a - safety measure to prevent passing the beginning of the string in the search for a - UTF-8 lead octet.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - previous code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">unsigned char</span>* w = twochars + <span class= -"literal">3</span>; -<span class="keyword">int</span> cp = prior (w, twochars); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars); -</pre> - <p> - This function has two purposes: one is two iterate backwards through a UTF-8 - encoded string. Note that it is usually a better idea to iterate forward instead, - since <code>utf8::next</code> is faster. The second purpose is to find a beginning - of a UTF-8 sequence if we have a random position within a string. Note that in that - case <code>utf8::prior</code> may not detect an invalid UTF-8 sequence in some scenarios: - for instance if there are superfluous trail octets, it will just skip them. - </p> - <p> - <code>it</code> will typically point to the beginning of - a code point, and <code>start</code> will point to the - beginning of the string to ensure we don't go backwards too far. <code>it</code> is - decreased until it points to a lead UTF-8 octet, and then the UTF-8 sequence - beginning with that octet is decoded to a 32 bit representation and returned. - </p> - <p> - In case <code>start</code> is reached before a UTF-8 lead octet is hit, or if an - invalid UTF-8 sequence is started by the lead octet, an <code>invalid_utf8</code> - exception is thrown. - </p> - <p>In case <code>start</code> equals <code>it</code>, a <code>not_enough_room</code> - exception is thrown. - <h4> - utf8::previous - </h4> - <p class="version"> - Deprecated in version 1.02 and later. - </p> - <p> - Given a reference to an iterator pointing to an octet in a UTF-8 seqence, it - decreases the iterator until it hits the beginning of the previous UTF-8 encoded - code point and returns the 32 bits representation of the code point. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t previous(octet_iterator& it, octet_iterator pass_start); - -</pre> - <p> - <code>octet_iterator</code>: a random access iterator.<br> - <code>it</code>: a reference pointing to an octet within a UTF-8 encoded string. - After the function returns, it is decremented to point to the beginning of the - previous code point.<br> - <code>pass_start</code>: an iterator to the point in the sequence where the search - for the beginning of a code point is aborted if no result was reached. It is a - safety measure to prevent passing the beginning of the string in the search for a - UTF-8 lead octet.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - previous code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">unsigned char</span>* w = twochars + <span class= -"literal">3</span>; -<span class="keyword">int</span> cp = previous (w, twochars - <span class= -"literal">1</span>); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars); -</pre> - <p> - <code>utf8::previous</code> is deprecated, and <code>utf8::prior</code> should - be used instead, although the existing code can continue using this function. - The problem is the parameter <code>pass_start</code> that points to the position - just before the beginning of the sequence. Standard containers don't have the - concept of "pass start" and the function can not be used with their iterators. - </p> - <p> - <code>it</code> will typically point to the beginning of - a code point, and <code>pass_start</code> will point to the octet just before the - beginning of the string to ensure we don't go backwards too far. <code>it</code> is - decreased until it points to a lead UTF-8 octet, and then the UTF-8 sequence - beginning with that octet is decoded to a 32 bit representation and returned. - </p> - <p> - In case <code>pass_start</code> is reached before a UTF-8 lead octet is hit, or if an - invalid UTF-8 sequence is started by the lead octet, an <code>invalid_utf8</code> - exception is thrown - </p> - <h4> - utf8::advance - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Advances an iterator by the specified number of code points within an UTF-8 - sequence. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, typename distance_type> -<span class= -"keyword">void</span> advance (octet_iterator& it, distance_type n, octet_iterator end); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>distance_type</code>: an integral type convertible to <code>octet_iterator</code>'s difference type.<br> - <code>it</code>: a reference to an iterator pointing to the beginning of an UTF-8 - encoded code point. After the function returns, it is incremented to point to the - nth following code point.<br> - <code>n</code>: a positive integer that shows how many code points we want to - advance.<br> - <code>end</code>: end of the UTF-8 sequence to be processed. If <code>it</code> - gets equal to <code>end</code> during the extraction of a code point, an - <code>utf8::not_enough_room</code> exception is thrown.<br> - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">unsigned char</span>* w = twochars; -advance (w, <span class="literal">2</span>, twochars + <span class="literal">6</span>); -assert (w == twochars + <span class="literal">5</span>); -</pre> - <p> - This function works only "forward". In case of a negative <code>n</code>, there is - no effect. - </p> - <p> - In case of an invalid code point, a <code>utf8::invalid_code_point</code> exception - is thrown. - </p> - <h4> - utf8::distance - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Given the iterators to two UTF-8 encoded code points in a seqence, returns the - number of code points between them. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -<span class= -"keyword">typename</span> std::iterator_traits<octet_iterator>::difference_type distance (octet_iterator first, octet_iterator last); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>first</code>: an iterator to a beginning of a UTF-8 encoded code point.<br> - <code>last</code>: an iterator to a "post-end" of the last UTF-8 encoded code - point in the sequence we are trying to determine the length. It can be the - beginning of a new code point, or not.<br> - <span class="return_value">Return value</span> the distance between the iterators, - in code points. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -size_t dist = utf8::distance(twochars, twochars + <span class="literal">5</span>); -assert (dist == <span class="literal">2</span>); -</pre> - <p> - This function is used to find the length (in code points) of a UTF-8 encoded - string. The reason it is called <em>distance</em>, rather than, say, - <em>length</em> is mainly because developers are used that <em>length</em> is an - O(1) function. Computing the length of an UTF-8 string is a linear operation, and - it looked better to model it after <code>std::distance</code> algorithm. - </p> - <p> - In case of an invalid UTF-8 seqence, a <code>utf8::invalid_utf8</code> exception is - thrown. If <code>last</code> does not point to the past-of-end of a UTF-8 seqence, - a <code>utf8::not_enough_room</code> exception is thrown. - </p> - <h4> - utf8::utf16to8 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts a UTF-16 encoded string to UTF-8. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> u16bit_iterator, <span class= -"keyword">typename</span> octet_iterator> -octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result); - -</pre> - <p> - <code>u16bit_iterator</code>: an input iterator.<br> - <code>octet_iterator</code>: an output iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-16 encoded - string to convert.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-16 encoded - string to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-8 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-8 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">unsigned short</span> utf16string[] = {<span class= -"literal">0x41</span>, <span class="literal">0x0448</span>, <span class= -"literal">0x65e5</span>, <span class="literal">0xd834</span>, <span class= -"literal">0xdd1e</span>}; -vector<<span class="keyword">unsigned char</span>> utf8result; -utf16to8(utf16string, utf16string + <span class= -"literal">5</span>, back_inserter(utf8result)); -assert (utf8result.size() == <span class="literal">10</span>); -</pre> - <p> - In case of invalid UTF-16 sequence, a <code>utf8::invalid_utf16</code> exception is - thrown. - </p> - <h4> - utf8::utf8to16 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts an UTF-8 encoded string to UTF-16 - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> u16bit_iterator, typename octet_iterator> -u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>u16bit_iterator</code>: an output iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 encoded - string to convert. < br /> <code>end</code>: an iterator pointing to - pass-the-end of the UTF-8 encoded string to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-16 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-16 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span> utf8_with_surrogates[] = <span class= -"literal">"\xe6\x97\xa5\xd1\x88\xf0\x9d\x84\x9e"</span>; -vector <<span class="keyword">unsigned short</span>> utf16result; -utf8to16(utf8_with_surrogates, utf8_with_surrogates + <span class= -"literal">9</span>, back_inserter(utf16result)); -assert (utf16result.size() == <span class="literal">4</span>); -assert (utf16result[<span class="literal">2</span>] == <span class= -"literal">0xd834</span>); -assert (utf16result[<span class="literal">3</span>] == <span class= -"literal">0xdd1e</span>); -</pre> - <p> - In case of an invalid UTF-8 seqence, a <code>utf8::invalid_utf8</code> exception is - thrown. If <code>end</code> does not point to the past-of-end of a UTF-8 seqence, a - <code>utf8::not_enough_room</code> exception is thrown. - </p> - <h4> - utf8::utf32to8 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts a UTF-32 encoded string to UTF-8. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, typename u32bit_iterator> -octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result); - -</pre> - <p> - <code>octet_iterator</code>: an output iterator.<br> - <code>u32bit_iterator</code>: an input iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-32 encoded - string to convert.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-32 encoded - string to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-8 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-8 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">int</span> utf32string[] = {<span class= -"literal">0x448</span>, <span class="literal">0x65E5</span>, <span class= -"literal">0x10346</span>, <span class="literal">0</span>}; -vector<<span class="keyword">unsigned char</span>> utf8result; -utf32to8(utf32string, utf32string + <span class= -"literal">3</span>, back_inserter(utf8result)); -assert (utf8result.size() == <span class="literal">9</span>); -</pre> - <p> - In case of invalid UTF-32 string, a <code>utf8::invalid_code_point</code> exception - is thrown. - </p> - <h4> - utf8::utf8to32 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts a UTF-8 encoded string to UTF-32. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, <span class= -"keyword">typename</span> u32bit_iterator> -u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>u32bit_iterator</code>: an output iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 encoded - string to convert.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-8 encoded string - to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-32 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-32 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -vector<<span class="keyword">int</span>> utf32result; -utf8to32(twochars, twochars + <span class= -"literal">5</span>, back_inserter(utf32result)); -assert (utf32result.size() == <span class="literal">2</span>); -</pre> - <p> - In case of an invalid UTF-8 seqence, a <code>utf8::invalid_utf8</code> exception is - thrown. If <code>end</code> does not point to the past-of-end of a UTF-8 seqence, a - <code>utf8::not_enough_room</code> exception is thrown. - </p> - <h4> - utf8::find_invalid - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Detects an invalid sequence within a UTF-8 string. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -octet_iterator find_invalid(octet_iterator start, octet_iterator end); -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 string to - test for validity.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-8 string to test - for validity.<br> - <span class="return_value">Return value</span>: an iterator pointing to the first - invalid octet in the UTF-8 string. In case none were found, equals - <code>end</code>. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span> utf_invalid[] = <span class= -"literal">"\xe6\x97\xa5\xd1\x88\xfa"</span>; -<span class= -"keyword">char</span>* invalid = find_invalid(utf_invalid, utf_invalid + <span class= -"literal">6</span>); -assert (invalid == utf_invalid + <span class="literal">5</span>); -</pre> - <p> - This function is typically used to make sure a UTF-8 string is valid before - processing it with other functions. It is especially important to call it if before - doing any of the <em>unchecked</em> operations on it. - </p> - <h4> - utf8::is_valid - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Checks whether a sequence of octets is a valid UTF-8 string. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -<span class="keyword">bool</span> is_valid(octet_iterator start, octet_iterator end); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 string to - test for validity.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-8 string to test - for validity.<br> - <span class="return_value">Return value</span>: <code>true</code> if the sequence - is a valid UTF-8 string; <code>false</code> if not. - </p> - Example of use: -<pre> -<span class="keyword">char</span> utf_invalid[] = <span class= -"literal">"\xe6\x97\xa5\xd1\x88\xfa"</span>; -<span class="keyword">bool</span> bvalid = is_valid(utf_invalid, utf_invalid + <span -class="literal">6</span>); -assert (bvalid == false); -</pre> - <p> - <code>is_valid</code> is a shorthand for <code>find_invalid(start, end) == - end;</code>. You may want to use it to make sure that a byte seqence is a valid - UTF-8 string without the need to know where it fails if it is not valid. - </p> - <h4> - utf8::replace_invalid - </h4> - <p class="version"> - Available in version 2.0 and later. - </p> - <p> - Replaces all invalid UTF-8 sequences within a string with a replacement marker. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, <span class= -"keyword">typename</span> output_iterator> -output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out, uint32_t replacement); -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, <span class= -"keyword">typename</span> output_iterator> -output_iterator replace_invalid(octet_iterator start, octet_iterator end, output_iterator out); - -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>output_iterator</code>: an output iterator.<br> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 string to - look for invalid UTF-8 sequences.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-8 string to look - for invalid UTF-8 sequences.<br> - <code>out</code>: An output iterator to the range where the result of replacement - is stored.<br> - <code>replacement</code>: A Unicode code point for the replacement marker. The - version without this parameter assumes the value <code>0xfffd</code><br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the UTF-8 string with replaced invalid sequences. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span> invalid_sequence[] = <span class= -"literal">"a\x80\xe0\xa0\xc0\xaf\xed\xa0\x80z"</span>; -vector<<span class="keyword">char</span>> replace_invalid_result; -replace_invalid (invalid_sequence, invalid_sequence + sizeof(invalid_sequence), back_inserter(replace_invalid_result), <span - class="literal">'?'</span>); -bvalid = is_valid(replace_invalid_result.begin(), replace_invalid_result.end()); -assert (bvalid); -<span class="keyword">char</span>* fixed_invalid_sequence = <span class= -"literal">"a????z"</span>; -assert (std::equal(replace_invalid_result.begin(), replace_invalid_result.end(), fixed_invalid_sequence)); -</pre> - <p> - <code>replace_invalid</code> does not perform in-place replacement of invalid - sequences. Rather, it produces a copy of the original string with the invalid - sequences replaced with a replacement marker. Therefore, <code>out</code> must not - be in the <code>[start, end]</code> range. - </p> - <p> - If <code>end</code> does not point to the past-of-end of a UTF-8 sequence, a - <code>utf8::not_enough_room</code> exception is thrown. - </p> - <h4> - utf8::starts_with_bom - </h4> - <p class="version"> - Available in version 2.3 and later. Relaces deprecated <code>is_bom()</code> function. - </p> - <p> - Checks whether an octet sequence starts with a UTF-8 byte order mark (BOM) - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -<span class="keyword">bool</span> starts_with_bom (octet_iterator it, octet_iterator end); -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>it</code>: beginning of the octet sequence to check<br> - <code>end</code>: pass-end of the sequence to check<br> - <span class="return_value">Return value</span>: <code>true</code> if the sequence - starts with a UTF-8 byte order mark; <code>false</code> if not. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">unsigned char</span> byte_order_mark[] = {<span class= -"literal">0xef</span>, <span class="literal">0xbb</span>, <span class= -"literal">0xbf</span>}; -<span class="keyword">bool</span> bbom = starts_with_bom(byte_order_mark, byte_order_mark + <span class="keyword">sizeof</span>(byte_order_mark)); -assert (bbom == <span class="literal">true</span>); -</pre> - <p> - The typical use of this function is to check the first three bytes of a file. If - they form the UTF-8 BOM, we want to skip them before processing the actual UTF-8 - encoded text. - </p> - <h4> - utf8::is_bom - </h4> - <p class="version"> - Available in version 1.0 and later. Deprecated in version 2.3. <code>starts_with_bom()</code> should be used - instead. - </p> - <p> - Checks whether a sequence of three octets is a UTF-8 byte order mark (BOM) - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -<span class="keyword">bool</span> is_bom (octet_iterator it); <span class="comment"> // Deprecated</span> -</pre> - <p> - <code>octet_iterator</code>: an input iterator.<br> - <code>it</code>: beginning of the 3-octet sequence to check<br> - <span class="return_value">Return value</span>: <code>true</code> if the sequence - is UTF-8 byte order mark; <code>false</code> if not. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">unsigned char</span> byte_order_mark[] = {<span class= -"literal">0xef</span>, <span class="literal">0xbb</span>, <span class= -"literal">0xbf</span>}; -<span class="keyword">bool</span> bbom = is_bom(byte_order_mark); -assert (bbom == <span class="literal">true</span>); -</pre> - <p> - The typical use of this function is to check the first three bytes of a file. If - they form the UTF-8 BOM, we want to skip them before processing the actual UTF-8 - encoded text. - </p> - <p> - If a sequence is - shorter than three bytes, an invalid iterator will be dereferenced. Therefore, this function is deprecated - in favor of <code>starts_with_bom()</code>that takes the end of sequence as an argument. - </p> - <h3 id="typesutf8"> - Types From utf8 Namespace - </h3> - <h4>utf8::exception - </h4> - <p class="version"> - Available in version 2.3 and later. - </p> - <p> - Base class for the exceptions thrown by UTF CPP library functions. - </p> -<pre> -<span class="keyword">class</span> exception : <span class="keyword">public</span> std::exception {}; -</pre> - <p> - Example of use: - </p> -<pre> -<span class="keyword">try</span> { - code_that_uses_utf_cpp_library(); -} -<span class="keyword">catch</span>(<span class="keyword">const</span> utf8::exception& utfcpp_ex) { - cerr << utfcpp_ex.what(); -} -</pre> - - <h4>utf8::invalid_code_point - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Thrown by UTF8 CPP functions such as <code>advance</code> and <code>next</code> if an UTF-8 sequence represents and invalid code point. - </p> - -<pre> -<span class="keyword">class</span> invalid_code_point : <span class="keyword">public</span> exception { -<span class="keyword">public</span>: - uint32_t code_point() <span class="keyword">const</span>; -}; - -</pre> - <p> - Member function <code>code_point()</code> can be used to determine the invalid code point that - caused the exception to be thrown. - </p> - <h4>utf8::invalid_utf8 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Thrown by UTF8 CPP functions such as <code>next</code> and <code>prior</code> if an invalid UTF-8 sequence - is detected during decoding. - </p> - -<pre> -<span class="keyword">class</span> invalid_utf8 : <span class="keyword">public</span> exception { -<span class="keyword">public</span>: - uint8_t utf8_octet() <span class="keyword">const</span>; -}; -</pre> - - <p> - Member function <code>utf8_octet()</code> can be used to determine the beginning of the byte - sequence that caused the exception to be thrown. - </p> -</pre> - <h4>utf8::invalid_utf16 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Thrown by UTF8 CPP function <code>utf16to8</code> if an invalid UTF-16 sequence - is detected during decoding. - </p> - -<pre> -<span class="keyword">class</span> invalid_utf16 : <span class="keyword">public</span> exception { -<span class="keyword">public</span>: - uint16_t utf16_word() <span class="keyword">const</span>; -}; -</pre> - - <p> - Member function <code>utf16_word()</code> can be used to determine the UTF-16 code unit - that caused the exception to be thrown. - </p> - <h4>utf8::not_enough_room - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Thrown by UTF8 CPP functions such as <code>next</code> if the end of the decoded UTF-8 sequence - was reached before the code point was decoded. - </p> - -<pre> -<span class="keyword">class</span> not_enough_room : <span class="keyword">public</span> exception {}; -</pre> - <h4> - utf8::iterator - </h4> - <p class="version"> - Available in version 2.0 and later. - </p> - <p> - Adapts the underlying octet iterator to iterate over the sequence of code points, - rather than raw octets. - </p> -<pre> -<span class="keyword">template</span> <<span class="keyword">typename</span> octet_iterator> -<span class="keyword">class</span> iterator; -</pre> - - <h5>Member functions</h5> - <dl> - <dt><code>iterator();</code> <dd> the deafult constructor; the underlying <code>octet_iterator</code> is - constructed with its default constructor. - <dt><code><span class="keyword">explicit</span> iterator (const octet_iterator& octet_it, - const octet_iterator& range_start, - const octet_iterator& range_end);</code> <dd> a constructor - that initializes the underlying <code>octet_iterator</code> with <code>octet_it</code> - and sets the range in which the iterator is considered valid. - <dt><code>octet_iterator base () <span class="keyword">const</span>;</code> <dd> returns the - underlying <code>octet_iterator</code>. - <dt><code>uint32_t operator * () <span class="keyword">const</span>;</code> <dd> decodes the utf-8 sequence - the underlying <code>octet_iterator</code> is pointing to and returns the code point. - <dt><code><span class="keyword">bool operator</span> == (const iterator& rhs) - <span class="keyword">const</span>;</code> <dd> returns <span class="keyword">true</span> - if the two underlaying iterators are equal. - <dt><code><span class="keyword">bool operator</span> != (const iterator& rhs) - <span class="keyword">const</span>;</code> <dd> returns <span class="keyword">true</span> - if the two underlaying iterators are not equal. - <dt><code>iterator& <span class="keyword">operator</span> ++ (); </code> <dd> the prefix increment - moves - the iterator to the next UTF-8 encoded code point. - <dt><code>iterator <span class="keyword">operator</span> ++ (<span class="keyword">int</span>); </code> <dd> - the postfix increment - moves the iterator to the next UTF-8 encoded code point and returns the current one. - <dt><code>iterator& <span class="keyword">operator</span> -- (); </code> <dd> the prefix decrement - moves - the iterator to the previous UTF-8 encoded code point. - <dt><code>iterator <span class="keyword">operator</span> -- (<span class="keyword">int</span>); </code> <dd> - the postfix decrement - moves the iterator to the previous UTF-8 encoded code point and returns the current one. - </dl> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* threechars = <span class="literal">"\xf0\x90\x8d\x86\xe6\x97\xa5\xd1\x88"</span>; -utf8::iterator<<span class="keyword">char</span>*> it(threechars, threechars, threechars + <span class="literal">9</span>); -utf8::iterator<<span class="keyword">char</span>*> it2 = it; -assert (it2 == it); -assert (*it == <span class="literal">0x10346</span>); -assert (*(++it) == <span class="literal">0x65e5</span>); -assert ((*it++) == <span class="literal">0x65e5</span>); -assert (*it == <span class="literal">0x0448</span>); -assert (it != it2); -utf8::iterator<<span class="keyword">char</span>*> endit (threechars + <span class="literal">9</span>, threechars, threechars + <span class="literal">9</span>); -assert (++it == endit); -assert (*(--it) == <span class="literal">0x0448</span>); -assert ((*it--) == <span class="literal">0x0448</span>); -assert (*it == <span class="literal">0x65e5</span>); -assert (--it == utf8::iterator<<span class="keyword">char</span>*>(threechars, threechars, threechars + <span class="literal">9</span>)); -assert (*it == <span class="literal">0x10346</span>); -</pre> - <p> - The purpose of <code>utf8::iterator</code> adapter is to enable easy iteration as well as the use of STL - algorithms with UTF-8 encoded strings. Increment and decrement operators are implemented in terms of - <code>utf8::next()</code> and <code>utf8::prior()</code> functions. - </p> - <p> - Note that <code>utf8::iterator</code> adapter is a checked iterator. It operates on the range specified in - the constructor; any attempt to go out of that range will result in an exception. Even the comparison operators - require both iterator object to be constructed against the same range - otherwise an exception is thrown. Typically, - the range will be determined by sequence container functions <code>begin</code> and <code>end</code>, i.e.: - </p> -<pre> -std::string s = <span class="literal">"example"</span>; -utf8::iterator i (s.begin(), s.begin(), s.end()); -</pre> - <h3 id="fununchecked"> - Functions From utf8::unchecked Namespace - </h3> - <h4> - utf8::unchecked::append - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Encodes a 32 bit code point as a UTF-8 sequence of octets and appends the sequence - to a UTF-8 string. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -octet_iterator append(uint32_t cp, octet_iterator result); - -</pre> - <p> - <code>cp</code>: A 32 bit integer representing a code point to append to the - sequence.<br> - <code>result</code>: An output iterator to the place in the sequence where to - append the code point.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the newly appended sequence. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">unsigned char</span> u[<span class="literal">5</span>] = {<span -class="literal">0</span>,<span class="literal">0</span>,<span class= -"literal">0</span>,<span class="literal">0</span>,<span class="literal">0</span>}; -<span class="keyword">unsigned char</span>* end = unchecked::append(<span class= -"literal">0x0448</span>, u); -assert (u[<span class="literal">0</span>] == <span class= -"literal">0xd1</span> && u[<span class="literal">1</span>] == <span class= -"literal">0x88</span> && u[<span class="literal">2</span>] == <span class= -"literal">0</span> && u[<span class="literal">3</span>] == <span class= -"literal">0</span> && u[<span class="literal">4</span>] == <span class= -"literal">0</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::append</code>. It does not - check for validity of the supplied code point, and may produce an invalid UTF-8 - sequence. - </p> - <h4> - utf8::unchecked::next - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Given the iterator to the beginning of a UTF-8 sequence, it returns the code point - and moves the iterator to the next position. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t next(octet_iterator& it); - -</pre> - <p> - <code>it</code>: a reference to an iterator pointing to the beginning of an UTF-8 - encoded code point. After the function returns, it is incremented to point to the - beginning of the next code point.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - processed UTF-8 code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars; -<span class="keyword">int</span> cp = unchecked::next(w); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars + <span class="literal">3</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::next</code>. It does not - check for validity of the supplied UTF-8 sequence. - </p> - <h4> - utf8::unchecked::peek_next - </h4> - <p class="version"> - Available in version 2.1 and later. - </p> - <p> - Given the iterator to the beginning of a UTF-8 sequence, it returns the code point. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t peek_next(octet_iterator it); - -</pre> - <p> - <code>it</code>: an iterator pointing to the beginning of an UTF-8 - encoded code point.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - processed UTF-8 code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars; -<span class="keyword">int</span> cp = unchecked::peek_next(w); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars); -</pre> - <p> - This is a faster but less safe version of <code>utf8::peek_next</code>. It does not - check for validity of the supplied UTF-8 sequence. - </p> - <h4> - utf8::unchecked::prior - </h4> - <p class="version"> - Available in version 1.02 and later. - </p> - <p> - Given a reference to an iterator pointing to an octet in a UTF-8 seqence, it - decreases the iterator until it hits the beginning of the previous UTF-8 encoded - code point and returns the 32 bits representation of the code point. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t prior(octet_iterator& it); - -</pre> - <p> - <code>it</code>: a reference pointing to an octet within a UTF-8 encoded string. - After the function returns, it is decremented to point to the beginning of the - previous code point.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - previous code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars + <span class="literal">3</span>; -<span class="keyword">int</span> cp = unchecked::prior (w); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars); -</pre> - <p> - This is a faster but less safe version of <code>utf8::prior</code>. It does not - check for validity of the supplied UTF-8 sequence and offers no boundary checking. - </p> - <h4> - utf8::unchecked::previous (deprecated, see utf8::unchecked::prior) - </h4> - <p class="version"> - Deprecated in version 1.02 and later. - </p> - <p> - Given a reference to an iterator pointing to an octet in a UTF-8 seqence, it - decreases the iterator until it hits the beginning of the previous UTF-8 encoded - code point and returns the 32 bits representation of the code point. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -uint32_t previous(octet_iterator& it); - -</pre> - <p> - <code>it</code>: a reference pointing to an octet within a UTF-8 encoded string. - After the function returns, it is decremented to point to the beginning of the - previous code point.<br> - <span class="return_value">Return value</span>: the 32 bit representation of the - previous code point. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars + <span class="literal">3</span>; -<span class="keyword">int</span> cp = unchecked::previous (w); -assert (cp == <span class="literal">0x65e5</span>); -assert (w == twochars); -</pre> - <p> - The reason this function is deprecated is just the consistency with the "checked" - versions, where <code>prior</code> should be used instead of <code>previous</code>. - In fact, <code>unchecked::previous</code> behaves exactly the same as <code> - unchecked::prior</code> - </p> - <p> - This is a faster but less safe version of <code>utf8::previous</code>. It does not - check for validity of the supplied UTF-8 sequence and offers no boundary checking. - </p> - <h4> - utf8::unchecked::advance - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Advances an iterator by the specified number of code points within an UTF-8 - sequence. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, typename distance_type> -<span class="keyword">void</span> advance (octet_iterator& it, distance_type n); - -</pre> - <p> - <code>it</code>: a reference to an iterator pointing to the beginning of an UTF-8 - encoded code point. After the function returns, it is incremented to point to the - nth following code point.<br> - <code>n</code>: a positive integer that shows how many code points we want to - advance.<br> - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -<span class="keyword">char</span>* w = twochars; -unchecked::advance (w, <span class="literal">2</span>); -assert (w == twochars + <span class="literal">5</span>); -</pre> - <p> - This function works only "forward". In case of a negative <code>n</code>, there is - no effect. - </p> - <p> - This is a faster but less safe version of <code>utf8::advance</code>. It does not - check for validity of the supplied UTF-8 sequence and offers no boundary checking. - </p> - <h4> - utf8::unchecked::distance - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Given the iterators to two UTF-8 encoded code points in a seqence, returns the - number of code points between them. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator> -<span class= -"keyword">typename</span> std::iterator_traits<octet_iterator>::difference_type distance (octet_iterator first, octet_iterator last); -</pre> - <p> - <code>first</code>: an iterator to a beginning of a UTF-8 encoded code point.<br> - <code>last</code>: an iterator to a "post-end" of the last UTF-8 encoded code - point in the sequence we are trying to determine the length. It can be the - beginning of a new code point, or not.<br> - <span class="return_value">Return value</span> the distance between the iterators, - in code points. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -size_t dist = utf8::unchecked::distance(twochars, twochars + <span class= -"literal">5</span>); -assert (dist == <span class="literal">2</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::distance</code>. It does not - check for validity of the supplied UTF-8 sequence. - </p> - <h4> - utf8::unchecked::utf16to8 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts a UTF-16 encoded string to UTF-8. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> u16bit_iterator, <span class= -"keyword">typename</span> octet_iterator> -octet_iterator utf16to8 (u16bit_iterator start, u16bit_iterator end, octet_iterator result); - -</pre> - <p> - <code>start</code>: an iterator pointing to the beginning of the UTF-16 encoded - string to convert.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-16 encoded - string to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-8 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-8 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">unsigned short</span> utf16string[] = {<span class= -"literal">0x41</span>, <span class="literal">0x0448</span>, <span class= -"literal">0x65e5</span>, <span class="literal">0xd834</span>, <span class= -"literal">0xdd1e</span>}; -vector<<span class="keyword">unsigned char</span>> utf8result; -unchecked::utf16to8(utf16string, utf16string + <span class= -"literal">5</span>, back_inserter(utf8result)); -assert (utf8result.size() == <span class="literal">10</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::utf16to8</code>. It does not - check for validity of the supplied UTF-16 sequence. - </p> - <h4> - utf8::unchecked::utf8to16 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts an UTF-8 encoded string to UTF-16 - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> u16bit_iterator, typename octet_iterator> -u16bit_iterator utf8to16 (octet_iterator start, octet_iterator end, u16bit_iterator result); - -</pre> - <p> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 encoded - string to convert. < br /> <code>end</code>: an iterator pointing to - pass-the-end of the UTF-8 encoded string to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-16 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-16 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span> utf8_with_surrogates[] = <span class= -"literal">"\xe6\x97\xa5\xd1\x88\xf0\x9d\x84\x9e"</span>; -vector <<span class="keyword">unsigned short</span>> utf16result; -unchecked::utf8to16(utf8_with_surrogates, utf8_with_surrogates + <span class= -"literal">9</span>, back_inserter(utf16result)); -assert (utf16result.size() == <span class="literal">4</span>); -assert (utf16result[<span class="literal">2</span>] == <span class= -"literal">0xd834</span>); -assert (utf16result[<span class="literal">3</span>] == <span class= -"literal">0xdd1e</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::utf8to16</code>. It does not - check for validity of the supplied UTF-8 sequence. - </p> - <h4> - utf8::unchecked::utf32to8 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts a UTF-32 encoded string to UTF-8. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, <span class= -"keyword">typename</span> u32bit_iterator> -octet_iterator utf32to8 (u32bit_iterator start, u32bit_iterator end, octet_iterator result); - -</pre> - <p> - <code>start</code>: an iterator pointing to the beginning of the UTF-32 encoded - string to convert.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-32 encoded - string to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-8 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-8 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">int</span> utf32string[] = {<span class= -"literal">0x448</span>, <span class="literal">0x65e5</span>, <span class= -"literal">0x10346</span>, <span class="literal">0</span>}; -vector<<span class="keyword">unsigned char</span>> utf8result; -utf32to8(utf32string, utf32string + <span class= -"literal">3</span>, back_inserter(utf8result)); -assert (utf8result.size() == <span class="literal">9</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::utf32to8</code>. It does not - check for validity of the supplied UTF-32 sequence. - </p> - <h4> - utf8::unchecked::utf8to32 - </h4> - <p class="version"> - Available in version 1.0 and later. - </p> - <p> - Converts a UTF-8 encoded string to UTF-32. - </p> -<pre> -<span class="keyword">template</span> <<span class= -"keyword">typename</span> octet_iterator, typename u32bit_iterator> -u32bit_iterator utf8to32 (octet_iterator start, octet_iterator end, u32bit_iterator result); - -</pre> - <p> - <code>start</code>: an iterator pointing to the beginning of the UTF-8 encoded - string to convert.<br> - <code>end</code>: an iterator pointing to pass-the-end of the UTF-8 encoded string - to convert.<br> - <code>result</code>: an output iterator to the place in the UTF-32 string where to - append the result of conversion.<br> - <span class="return_value">Return value</span>: An iterator pointing to the place - after the appended UTF-32 string. - </p> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* twochars = <span class= -"literal">"\xe6\x97\xa5\xd1\x88"</span>; -vector<<span class="keyword">int</span>> utf32result; -unchecked::utf8to32(twochars, twochars + <span class= -"literal">5</span>, back_inserter(utf32result)); -assert (utf32result.size() == <span class="literal">2</span>); -</pre> - <p> - This is a faster but less safe version of <code>utf8::utf8to32</code>. It does not - check for validity of the supplied UTF-8 sequence. - </p> - <h3 id="typesunchecked"> - Types From utf8::unchecked Namespace - </h3> - <h4> - utf8::iterator - </h4> - <p class="version"> - Available in version 2.0 and later. - </p> - <p> - Adapts the underlying octet iterator to iterate over the sequence of code points, - rather than raw octets. - </p> -<pre> -<span class="keyword">template</span> <<span class="keyword">typename</span> octet_iterator> -<span class="keyword">class</span> iterator; -</pre> - - <h5>Member functions</h5> - <dl> - <dt><code>iterator();</code> <dd> the deafult constructor; the underlying <code>octet_iterator</code> is - constructed with its default constructor. - <dt><code><span class="keyword">explicit</span> iterator (const octet_iterator& octet_it); - </code> <dd> a constructor - that initializes the underlying <code>octet_iterator</code> with <code>octet_it</code> - <dt><code>octet_iterator base () <span class="keyword">const</span>;</code> <dd> returns the - underlying <code>octet_iterator</code>. - <dt><code>uint32_t operator * () <span class="keyword">const</span>;</code> <dd> decodes the utf-8 sequence - the underlying <code>octet_iterator</code> is pointing to and returns the code point. - <dt><code><span class="keyword">bool operator</span> == (const iterator& rhs) - <span class="keyword">const</span>;</code> <dd> returns <span class="keyword">true</span> - if the two underlaying iterators are equal. - <dt><code><span class="keyword">bool operator</span> != (const iterator& rhs) - <span class="keyword">const</span>;</code> <dd> returns <span class="keyword">true</span> - if the two underlaying iterators are not equal. - <dt><code>iterator& <span class="keyword">operator</span> ++ (); </code> <dd> the prefix increment - moves - the iterator to the next UTF-8 encoded code point. - <dt><code>iterator <span class="keyword">operator</span> ++ (<span class="keyword">int</span>); </code> <dd> - the postfix increment - moves the iterator to the next UTF-8 encoded code point and returns the current one. - <dt><code>iterator& <span class="keyword">operator</span> -- (); </code> <dd> the prefix decrement - moves - the iterator to the previous UTF-8 encoded code point. - <dt><code>iterator <span class="keyword">operator</span> -- (<span class="keyword">int</span>); </code> <dd> - the postfix decrement - moves the iterator to the previous UTF-8 encoded code point and returns the current one. - </dl> - <p> - Example of use: - </p> -<pre> -<span class="keyword">char</span>* threechars = <span class="literal">"\xf0\x90\x8d\x86\xe6\x97\xa5\xd1\x88"</span>; -utf8::unchecked::iterator<<span class="keyword">char</span>*> un_it(threechars); -utf8::unchecked::iterator<<span class="keyword">char</span>*> un_it2 = un_it; -assert (un_it2 == un_it); -assert (*un_it == <span class="literal">0x10346</span>); -assert (*(++un_it) == <span class="literal">0x65e5</span>); -assert ((*un_it++) == <span class="literal">0x65e5</span>); -assert (*un_it == <span class="literal">0x0448</span>); -assert (un_it != un_it2); -utf8::::unchecked::iterator<<span class="keyword">char</span>*> un_endit (threechars + <span class="literal">9</span>); -assert (++un_it == un_endit); -assert (*(--un_it) == <span class="literal">0x0448</span>); -assert ((*un_it--) == <span class="literal">0x0448</span>); -assert (*un_it == <span class="literal">0x65e5</span>); -assert (--un_it == utf8::unchecked::iterator<<span class="keyword">char</span>*>(threechars)); -assert (*un_it == <span class="literal">0x10346</span>); -</pre> - <p> - This is an unchecked version of <code>utf8::iterator</code>. It is faster in many cases, but offers - no validity or range checks. - </p> - <h2 id="points"> - Points of interest - </h2> - <h4> - Design goals and decisions - </h4> - <p> - The library was designed to be: - </p> - <ol> - <li> - Generic: for better or worse, there are many C++ string classes out there, and - the library should work with as many of them as possible. - </li> - <li> - Portable: the library should be portable both accross different platforms and - compilers. The only non-portable code is a small section that declares unsigned - integers of different sizes: three typedefs. They can be changed by the users of - the library if they don't match their platform. The default setting should work - for Windows (both 32 and 64 bit), and most 32 bit and 64 bit Unix derivatives. - </li> - <li> - Lightweight: follow the "pay only for what you use" guideline. - </li> - <li> - Unintrusive: avoid forcing any particular design or even programming style on the - user. This is a library, not a framework. - </li> - </ol> - <h4> - Alternatives - </h4> - <p> - In case you want to look into other means of working with UTF-8 strings from C++, - here is the list of solutions I am aware of: - </p> - <ol> - <li> - <a href="http://icu.sourceforge.net/">ICU Library</a>. It is very powerful, - complete, feature-rich, mature, and widely used. Also big, intrusive, - non-generic, and doesn't play well with the Standard Library. I definitelly - recommend looking at ICU even if you don't plan to use it. - </li> - <li> - C++11 language and library features. Still far from complete, and not widely - supported by compiler vendors. - </li> - <li> - <a href= - "http://www.gtkmm.org/gtkmm2/docs/tutorial/html/ch03s04.html">Glib::ustring</a>. - A class specifically made to work with UTF-8 strings, and also feel like - <code>std::string</code>. If you prefer to have yet another string class in your - code, it may be worth a look. Be aware of the licensing issues, though. - </li> - <li> - Platform dependent solutions: Windows and POSIX have functions to convert strings - from one encoding to another. That is only a subset of what my library offers, - but if that is all you need it may be good enough. - </li> - </ol> - <h2 id="links"> - Links - </h2> - <ol> - <li> - <a href="http://www.unicode.org/">The Unicode Consortium</a>. - </li> - <li> - <a href="http://icu.sourceforge.net/">ICU Library</a>. - </li> - <li> - <a href="http://en.wikipedia.org/wiki/UTF-8">UTF-8 at Wikipedia</a> - </li> - <li> - <a href="http://www.cl.cam.ac.uk/~mgk25/unicode.html">UTF-8 and Unicode FAQ for - Unix/Linux</a> - </li> - </ol> - </body> -</html> |