__vic/doc/en/base16.h.xml

<chapter xml:id="base16.h">
<title><tt>__vic/base16.h</tt></title>

<p>Base16 encoder and decoder.</p>


<chapter xml:id="base16">
<title><tt>base16</tt></title>

<p>A class used as a namespace. Contains only types, constants and static
functions. No objects of this class are supposed to be created.</p>

</chapter>


<chapter xml:id="base16--bad_format">
<title><tt>base16::bad_format</tt></title>

<code-block lang="C++">
struct base16::bad_format : public std::exception {};
</code-block>

<p>Abstract base exception class.</p>

</chapter>


<chapter xml:id="base16--bad_digit">
<title><tt>base16::bad_digit</tt></title>

<code-block lang="C++">
struct base16::bad_digit : public base16::bad_format
{
    const char *what() const noexcept;
};
</code-block>

<p>Exception class thrown by <xref to="base16--decode"/> when the input sequence
contains character that is not a valid HEX digit.</p>

</chapter>


<chapter xml:id="base16--bad_length">
<title><tt>base16::bad_length</tt></title>

<code-block lang="C++">
struct base16::bad_length : public base16::bad_format
{
    const char *what() const noexcept;
};
</code-block>

<p>Exception class thrown by <xref to="base16--decode"/> when the input sequence
length is odd.</p>

</chapter>


<chapter xml:id="base16--status">
<title><tt>base16::status</tt></title>

<code-block lang="C++">
enum class base16::status
{
    ok,
    invalid_length,
    invalid_digit
};
using base16::status_t = base16::status; // for C++98
</code-block>

<p>Input sequence parsing outcome status codes returned by
<xref to="base16--try_decode"/>.</p>

</chapter>


<chapter xml:id="base16--encode_upper">
<title><tt>base16::encode_upper()</tt></title>

<code-block lang="C++"><![CDATA[
// Bytes -> Text
template<class ByteReader, class CharWriter>
void base16::encode_upper(ByteReader reader, CharWriter writer);
]]></code-block>

<p>Encodes bytes from <tt>reader</tt> and writes the resulting characters to
<tt>writer</tt>. Upper case is used for hexadecimal digits.</p>

<p><tt>ByteReader</tt> has to model <tt>Reader&lt;unsigned char></tt> concept.
See <xref to="readers"/>.</p>

<p><tt>CharWriter</tt> has to model <tt>Writer&lt;char></tt> concept.
See <xref to="writers"/>.</p>


<section><title>Example</title>
<code-block lang="C++"><![CDATA[
#include<__vic/readers/string.h>
#include<__vic/writers/string.h>

using bytes = std::string;
using bytes_reader = __vic::string_reader;

std::string encode_base16(const bytes &s)
{
    std::string res;
    res.reserve(s.length() * 2);
    __vic::base16::encode_upper(bytes_reader(s), __vic::string_writer(res));
    return res;
}
]]></code-block>
</section>

</chapter>


<chapter xml:id="base16--encode_lower">
<title><tt>base16::encode_lower()</tt></title>

<code-block lang="C++"><![CDATA[
// Bytes -> Text
template<class ByteReader, class CharWriter>
void base16::encode_lower(ByteReader reader, CharWriter writer);
]]></code-block>

<p>Same as <xref to="base16--encode_upper"/> but lower case is used for
hexadecimal digits.</p>

</chapter>


<chapter xml:id="base16--encode_byte_lower">
<title><tt>base16::encode_byte_lower()</tt></title>

<code-block lang="C++"><![CDATA[
// Byte -> Text
template<class CharWriter>
void base16::encode_byte_lower(unsigned char byte, CharWriter writer);
]]></code-block>

<p>Same as <xref to="base16--encode_lower"/> but encodes only single byte.</p>

</chapter>


<chapter xml:id="base16--encode_byte_upper">
<title><tt>base16::encode_byte_upper()</tt></title>

<code-block lang="C++"><![CDATA[
// Byte -> Text
template<class CharWriter>
void base16::encode_byte_upper(unsigned char byte, CharWriter writer);
]]></code-block>

<p>Same as <xref to="base16--encode_upper"/> but encodes only single byte.</p>

</chapter>


<chapter xml:id="base16--decode">
<title><tt>base16::decode()</tt></title>

<code-block lang="C++"><![CDATA[
// Text -> Bytes
template<class CharReader, class ByteWriter>
void base16::decode(CharReader reader, ByteWriter writer);
]]></code-block>

<p>Decodes characters from <tt>reader</tt> and writes the resulting bytes to
<tt>writer</tt>. Exception derived from <xref to="base16--bad_format"/> is
thrown if the input sequence has invalid Base16 format.</p>

<p><tt>CharReader</tt> has to model <tt>Reader&lt;char></tt> concept.
See <xref to="readers"/>.</p>

<p><tt>ByteWriter</tt> has to model <tt>Writer&lt;unsigned char></tt> concept.
See <xref to="writers"/>.</p>

<section><title>Example</title>
<code-block lang="C++"><![CDATA[
#include<__vic/readers/string.h>
#include<__vic/writers/string.h>

using bytes = std::string;
using bytes_writer = __vic::string_writer;

bytes decode_base16(const std::string &s)
{
    bytes res;
    res.reserve(s.length() / 2);
    __vic::base16::decode(__vic::string_reader(s), bytes_writer(res));
    return res;
}
]]></code-block>
</section>

</chapter>


<chapter xml:id="base16--try_decode">
<title><tt>base16::try_decode()</tt></title>

<code-block lang="C++"><![CDATA[
// Text -> Bytes
template<class CharReader, class ByteWriter>
base16::status_t base16::try_decode(CharReader reader, ByteWriter writer);
]]></code-block>

<p>Same as <xref to="base16--decode"/> but returns <xref to="base16--status"/>
different from <tt>base16::status::ok</tt> in case of invalid input sequence
instead of throwing exception.</p>

</chapter>


</chapter>