RWUConversionContext Class Reference
[Character Encoding Scheme Conversion]

Specifies the default character encoding scheme for conversions between narrow character strings and UTF-16 strings. More...

#include <rw/i18n/RWUConversionContext.h>

Inheritance diagram for RWUConversionContext:

List of all members.

Public Member Functions
	RWUConversionContext (const char *encoding=RWUConverterBase::getDefaultEncodingName())
	~RWUConversionContext ()

---

Detailed Description

RWUConversionContext specifies the default character encoding scheme to use for subsequent implicit conversions between narrow character strings and UTF-16 encoded Unicode strings.

RWUConversionContext combines the functionality provided by the RWUToUnicodeConversionContext and RWUFromUnicodeConversionContext to provide a single convenient means for specifying the encoding for conversions to and from Unicode.

RWUConversionContext uses the resource acquisition is initialization idiom to manage two internal, per-thread stacks of RWUFromUnicodeConversionContext instances and RWUToUnicodeConversionContext.

Note:

Instances of RWUConversionContext can only be constructed with static or automatic storage duration; dynamic allocation is not allowed. Do not create unnamed, temporary instances. The destructors for such objects pop the context off the context stack prematurely.

Examples

 #include <rw/i18n/RWUConversionContext.h>
 #include <rw/i18n/RWUString.h>
 #include <iostream>
 
 int
 main()
 {
   // Indicate that source and target strings
   // are encoded according to ISO-8859-1
   RWUConversionContext context("ISO-8859-1");
 
   // NOTE!  This won't work:  RWUConversionContext("ISO-8859-1");
 
   // Use implicit conversion to construct `str'
   RWUString str("ISO-8859-1");
 
   // Use implicit conversion to initialize `str2'
   RWUString str2 = " source:  ";
   str += str2;
 
   // Write an ISO-8859-1 encoded representation of
   // `str' to std::cout
   std::cout << str << "in ISO-8859-1" << std::endl;
 
   {
     // Create a nested conversion context
     RWUConversionContext nestedContext("Shift-JIS");
 
     // Write a Shift-JIS encoded representation of
     // `str' to std::cout
     std::cout << str << "in Shift-JIS" << std::endl;
 
     // Nested context goes out of scope
   }
   
   // Original context goes out of scope
   return 0;
 }

Program output:

 ISO-8859-1 source:  in ISO-8859-1
 ISO-8859-1 source:  in Shift-JIS

See also:

RWUToUnicodeConversionContext, RWUFromUnicodeConversionContext

---

Constructor & Destructor Documentation

RWUConversionContext::RWUConversionContext

(

const char *

encoding = RWUConverterBase::getDefaultEncodingName()

)

[inline]

Constructs an RWUConversionContext for the specified encoding. The conversion context specifies the default implicit conversion to use when automatically converting a sequence of bytes into an RWUString, an RWUString into a sequence of bytes, or both. The encoding name is encoded in US-ASCII, and must specify one of the names or aliases currently recognized by the Internationalization Module (see RWUAvailableEncodingList and RWUEncodingAliasList).

The specified conversion context remains in effect until another conversion of the same direction is specified, or until the conversion context instance goes out of scope and is destroyed.

Exceptions:

RWUException

Thrown to indicate that a converter could not be constructed for the specified encoding. The exception carries one of the following status codes:

• RWUMemoryAllocationError

  Indicates that the memory required by the converter could not be allocated.

• RWUFileAccessError

  Indicates that the requested converter could not be found.

RWUConversionContext::~RWUConversionContext

(

)

[inline]

Destructor. Destroys self and restores the conversion context that was in effect prior to the construction of this instance.